Osaze v. Gee

Filed 9/29/26 CERTIFIED FOR PUBLICATION IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA FIRST APPELLATE DISTRICT DIVISION TWO WESLEY OSAZE et al., Plaintiffs and Appellants, A173403 v. HILDA APARICIO GEE et al., (San Mateo County Super. Ct. No. 21-CIV-04015) Defendants and Respondents. Anya Valencia brought her daughter’s dog, Boogie, to Skyline Veterinary Hospital for a bath. When Boogie escaped from the grooming room, Valencia went after him and fell in the adjacent hallway where she landed headfirst on the floor and was found unresponsive. Emergency responders took her to the hospital, and she died three days later. Valencia’s husband and son sued the owner of Skyline and the owner of the building, for wrongful death. Defendants moved for summary judgment claiming plaintiffs could not prove that any negligent conduct or condition of the premises caused Valencia’s fall. Plaintiffs offered expert declarations, including one from a veterinarian who opined that the failure to secure the dog in the grooming room either by closing the door or placing restraints on the dog was negligent and a substantial factor in the accident. Biomechanical engineers, one of whom inspected the property and measured an unmarked rise in the flooring of 1 approximately 1.25 inches at the threshold between the grooming room and the hallway, evaluated the cause of the fall, considering the mechanics of tripping and falling and the nature of Valencia’s injuries, as well as the absence of other conditions that could have caused the fall. They concluded the most likely cause of Valencia’s fall was that she tripped at the threshold. Without discussing the experts’ reasoning or analysis, the trial court excluded the experts’ key opinions, which it labeled as mere “conjecture” and “speculation.” Having excluded plaintiffs’ evidence of causation, the court granted summary judgment to defendants. The trial court erred in excluding the opinions of plaintiffs’ expert witnesses by failing to undertake the analysis our high court outlined in Sargon Enterprises, Inc. v. University of Southern California (2012) 55 Cal.4th 747, 771 (Sargon). Further, in granting summary judgment, it failed to construe plaintiffs’ evidence liberally and draw reasonable inferences in their favor and instead usurped the function of the jury. We therefore reverse. I. BACKGROUND A. Undisputed Facts 1 The basic facts are undisputed. From 2018 until 2024, Hilda Aparicio- Gee, a veterinary technician, owned and operated Skyline in part of a building she leased from veterinarian, Mark Restani, who owned the building and also practiced there. Valencia worked part-time as a receptionist for Skyline at Restani’s building starting in 2018 but stopped in March 2020 due 1 Many of these facts are based on the depositions of defendants Gee and Restani, which plaintiffs submitted in evidence and provide far more detail than the declarations defendants proffered. 2 to concerns about the COVID-19 pandemic. She did not return to work after that. On August 4, 2020, Valencia, then 69 years old, brought her daughter’s dog, Boogie, to Skyline for grooming. Gee let Valencia in and instructed her to meet Gee upstairs. Valencia took Boogie to the second floor and waited by the kitchen until Gee came upstairs. Gee accompanied Valencia and Boogie to the grooming room. The grooming room opened onto a hallway. The door to the grooming room was propped open, held back against the wall by shelving. At one end of that wall was the tub. Between the tub and the doorway was the shelving which held shampoos, conditioners and towels, a broom and dustpan and small trash can. The grooming room contained a table in the middle, cages and various other items. At the time of the incident, there was no gate between the grooming room and the hallway to prevent animals from escaping, although a gate was installed after the incident for that purpose. Concrete flooring in the grooming room was approximately 1.25 inches lower than the linoleum flooring in the hallway. 2 Inside the grooming room, Gee filled the tub with water, while Valencia stood on the other side of the grooming table and removed Boogie’s collar, leash and harness. While Valencia was removing his harness, Boogie fled the grooming room, going out the door and down the adjacent hallway. Gee Defendants purported to dispute the 1.25-inch measurement made by 2 one of plaintiffs’ biomechanical engineer experts, claiming the photograph he took “shows the elevation change is 1⅛ inch, not 1¼ inch,” and they objected to that measurement in the expert’s declaration, but the trial court did not sustain it and we presume it was overruled. (Reid v. Google, Inc. (2010) 50 Cal.4th 512, 534 (Reid).) We need not discuss this “dispute,” because the expert stated the height difference was “approximately 1.25 inches,” defendants do not dispute there was a height difference of at least 1⅛ inch and the difference of ⅛ inch is immaterial to the experts’ analyses. 3 heard Valencia say, “Come on Boogie,” sounding annoyed, before she left the room. Then she heard a thud and went to see what had happened. While she was still in the grooming room at the tub, Gee could not see past the entryway from where she was standing and could not see Valencia once she was past the doorway; she did not see Valencia fall and did not know whether Valencia had tripped. She saw Valencia “just for a moment as she was walking past the doorway.” In the hallway, Gee saw that Valencia had fallen, and her body was still moving toward the far end of the 13-foot hallway. She ended up about halfway down the hallway, face-down with her left hand by her side and her head near, but not at, the far wall, where there was a grate. She was unresponsive. Gee did not move her before Restani came upstairs. Restani was downstairs when Valencia fell. He either heard the fall, or Gee or someone alerted him to go upstairs. Restani came upstairs. When he arrived, Valencia was lying face-down in the hallway, with her body parallel to the hallway, her head pointing toward the far wall and her legs pointing toward the grooming room. Her head was about a foot, plus or minus a few inches, from the end of the hallway with the grate. 3 Valencia was 3 With their reply papers, defendants submitted supplemental declarations of Gee and Restani, the latter attaching an “errata” to his deposition stating that he now estimated Valencia’s head was “no more than 6 inches from the wall.” Both the supplemental declarations and the errata were filed well after plaintiffs filed their opposition to motion and, as far as we can tell, without a request to late-file new evidence. New evidence submitted in support of a summary judgment motion after the opposition has been filed violates the summary judgment statute. (See Code Civ. Proc., §437c, subd. (a)(2) [moving papers, including affidavits, etc., shall be filed not less than 81 days preceding hearing]; id., subd. (b)(1) [motion shall be supported by affidavits, declarations, etc.]; id., subd. (b)(4) [reply shall not include new evidentiary matter or facts not presented with opening papers].) None of the parties mention this late-filed evidence in their briefs on appeal, 4 unconscious and nonresponsive. Restani and Gee turned Valencia over. The dog ended up running downstairs. The doors were still locked so it ran to the reception area, and Gee or someone else put the dog in a cage. Someone at Skyline called 911 “right away.” Daly City Fire Department responded to the scene within about five minutes of the call and began resuscitation efforts, using defibrillation pads, a device for ventilation and an intravenous line with fluids. Private paramedics arrived at about 9:30 a.m. They asked Gee questions about what had happened, and she answered them. The paramedics reported finding Valencia on the second floor of the veterinarian clinic, lying supine and unresponsive, with a strong pulse but slow heart rate (bradycardia), interrupted breathing (apneic) and a hematoma with swelling and contusions on the frontal region of her head. They further reported that, “Per staff members the patient was chasing a dog down the hallway when she tripped and fell into the wall, struck the corner of her head, and fell unconscious on the marble floor.” At her deposition, Gee denied she told them that because “I don’t know if she tripped. . . . I couldn’t tell them what happened because I didn’t see.” The paramedics placed Valencia in a cervical collar, transferred her to the ambulance and assisted her breathing while transporting her to San Francisco General Hospital. Valencia remained unconscious and in critical condition throughout their emergency treatment. On the same day, Daly City Police came to Skyline, took photos, took a statement from Gee and prepared a report. The report described her statement. Among other things, she told police, “While she was preparing and the record does not reflect whether defendants requested to file it late or showed good cause for doing so. Nor is it clear whether the plaintiffs objected to it or whether the trial court considered it. We therefore do not consider it. 5 the tub Valencia was in the process of unharnessing the dog when it suddenly ran away. Valencia gave chase and the next thing was she heard a loud noise. She then found Valencia on the floor faced down with her left hand on her side, her right hand raised and her head slightly tilted to the left.” The hospital performed a CT scan and diagnosed Valencia with trauma and brain injury. After consulting with her family, the hospital placed her on comfort care, and she died at the hospital three days after the fall. The San Francisco Medical Examiner and Coroner’s office conducted an autopsy, finding contusions on Valencia’s forehead, right orbital, bridge of the nose and right upper lip and “subscalpular hemorrhage” and damage “with hemorrhage” to Valencia’s “cervical spinal cord.” Based on the examination of the body and scans taken by the hospital on the day Valencia was admitted, the autopsy report provided detailed information about her injuries and the conditions of her body and identified the cause of death as “blunt force injuries, head and neck,” specifically, “damage, cervical spinal cord,” “hemorrhage around foramen magnum,” 4 “subscalpular hemorrhage, frontal scalp,” “type II dens fracture without displacement, anterior arch and right lateral mass fracture of first cervical vertebra and frontal hematoma, . . . [and] cervical spinal cord injury edema with tearing of the longitudinal ligaments at first and second cervical vertebra.” The report established Valencia’s height was five feet, eight inches. At the time of Valencia’s fall, the floor in the hallway was not wet, the dog had not yet been bathed and was not wet and, apart from the raised threshold between the grooming room and hallway, no other tripping or 4 The foramen magnum is “the opening in the skull through which the spinal cord passes . . . .” (Merriam-Webster online dictionary <https://www.merriam-webster.com/dictionary/foramen%20magnum> (as of Sept. 29, 2026).) 6 falling hazards were present. When she arrived at Skyline that morning, Valencia showed no signs of illness or ingestion of alcohol or drugs that could have caused her to fall. After the incident, Gee put a low gate across the doorway to the grooming room to prevent animals from escaping. B. Procedural History Plaintiffs filed a complaint against defendants asserting negligence and premises liability against Skyline and Restani. 5 Defendants filed a general denial and asserted 11 affirmative defenses. Eventually, defendants filed a motion for summary judgment, asserting plaintiffs could not establish causation, an essential element of their negligence and premises liability claims. They argued, “There is simply no evidence that Decedent’s fall was caused by any condition of the floor on which she fell, nor any act or omission of Defendants.” Defendants did not attempt to prove a specific cause for Valencia’s fall. They simply argued that the fall was unwitnessed and could not have been caused by a trip on the raised threshold between the floor of the grooming room and the adjacent hallway, and that no other condition that could have caused her fall was identified. Absent evidence of causation, defendants argued, “Plaintiffs cannot establish all the elements necessary to carry their burden of proof.” The defense evidence the trial court admitted included a declaration by Gee stating that from where she was standing near the tub she could “clearly see the doorway leading to the hallway” but “could not see past the doorway into the hallway.” After Valencia removed the dog’s harness, it went into the hallway and Valencia followed. Gee asserted that Valencia “did not trip, stumble or fall” in the grooming room or at the threshold leading to the 5 The complaint names Restani as Trustee of the Restani Family Trust (the Trust). The building is owned by the Trust. 7 hallway. Gee did not see Valencia fall, and no one else was present in the hallway when she fell. In opposition, plaintiffs advanced two basic theories of causation that were not mutually exclusive. First, they argued, there was a 1.25-inch unmarked elevation change from the lower grooming room floor to the higher hallway floor that violated industry safety standards and state regulations and was a dangerous condition that caused Valencia to trip and fall. Further, they argued that by allowing a client into the employee-only grooming area, failing to restrain Valencia’s dog before its leash was removed, and leaving the grooming room door propped open allowing the dog to escape, Skyline violated “established safety protocols” for veterinary hospitals and, by doing so, set in motion the chain of events that led to Valencia’s fall. Plaintiffs proffered the declarations of two engineers with biomechanics expertise (Dr. Zachary Moore and Dr. John Gardiner) and one declaration of a veterinary doctor with expertise in veterinary hospital safety protocols (Dr. David Lahijaniha). C. Expert Declarations Plaintiffs submitted three expert declarations in opposition to summary judgment. Zachary Moore, a licensed mechanical engineer with expertise in forensic engineering, safety investigations and accident reconstruction, conducted a comprehensive site inspection of Skyline Pet Hospital to assess potential safety hazards and code violations and to document site conditions in the veterinary hospital’s grooming room and hallway area. He took measurements, performed a slip resistance analysis of the hallway floor, conducted a visual assessment, 3-D scan and took photographs and video evidence documenting the scene. He reviewed portions of the depositions of Gee and Restani, including attached exhibits consisting of photos of the 8 location on the day of the incident and post-incident, the autopsy report of Valencia, the defendants’ motion for summary judgment including declarations and exhibits, the paramedic report, articles, papers, statutes and regulations. His review of the evidence reflected that Valencia, aged 69, suffered an unwitnessed fall near the hallway adjacent to the second floor grooming room at Skyline. After she removed the dog’s harness in the grooming room, the dog rushed out the door and, while chasing after it, Valencia apparently fell and was found face-down about 13 inches away from the end of the hallway by Gee and later Restani. The hallway is approximately 156 inches in length (13 feet) and Valencia was 68 inches tall. The door to the grooming room was propped open and could not be closed on the day of the accident. At the threshold between the grooming room and hallway there was an elevation change of approximately 1.25 inches. Moore opined that the elevation change at the threshold “posed a significant trip and fall hazard to individuals exercising reasonable care because, as studies show, it “exceeds the minimum toe clearance (MTC) of the average pedestrian,” which “for most individuals is between 0.5 inches and 0.59 inches, meaning that the transition area in question was more than twice the height of an average person’s toe clearance.” Further, research shows “individuals do not always monitor the ground while walking, as their gaze is generally fixed ahead rather than downward,” and this is “particularly relevant in this case, where Anya Valencia was chasing a loose dog that had escaped from the grooming room,” and her “focus would have been on the animal rather than the ground in front of her.” The lack of warning signage, contrasting markings or visual indicators” to alert one to the transition “further compounded the risk.” 9  The 1.25-inch elevation change at the threshold violates current California Occupational Safety and Health Administration regulations, as well as Americans with Disabilities Act provisions that limit thresholds at doorways to a maximum of ½ inch, and the failure to mitigate it with “beveling, a ramp, or clear markings” created an “unnecessary and preventable hazard that contributed to the subject incident.” Even in older buildings not undergoing renovations, failure to adhere to these standards or provide simple fixes that could significantly reduce the risk of injury may be negligent and violate property owners’ obligation to ensure a reasonably safe environment. “In this case, the failure to take such precautionary measures allowed an unmitigated tripping hazard to remain in place, leading to the foreseeable injury and subsequent fatality of Anya Valencia.” Dr. John Gardiner, a registered professional engineer with a doctorate in bioengineering and expertise in investigation and assessment of injury mechanics, including slip/trip and fall events, reviewed the same case-specific summary judgment documents as Moore, the autopsy report and paramedics report, various cited papers and articles and Moore’s report, photos and measurements. His declaration set forth the following opinions: “Biomechanically, Ms. Valencia’s foot impacting or catching the 1.25 inch raised transition area [between the grooming room and hallway] is consistent with causing a trip that created her loss of balance and subsequent forward fall to the ground.” “A trip occurs when a person’s swinging foot contacts an obstruction which stops foot movement while forward momentum of the body continues,” and “[a] fall then occurs when the body’s center of mass is brought outside the base of support.” “Ms. Valencia’s foot contact with the 1.25 inch raised transition while stepping out of the [g]rooming [r]oom during pursuit of the dog is the most likely trip-inducing mechanism that initiated her fall.” 10 “Published research has shown that falls similar to [Valencia’s] are caused by uneven flooring or unexpected changes in ground level.” “The trip and fall event is often the initiating event leading to further injury by surface or ground contact . . . .” “[B]iomechanical studies show that individuals often stumble after tripping [and] can take forward steps as they attempt to recover balance before ultimately falling and impacting the ground.” “Stumbling or attempted recovery steps, particularly during a hurried forward motion are consistent with a fall further down the hallway rather than landing or tipping over directly at the tripping point. There may also be a sliding motion creating additional distance after ground impact.” Valencia’s “resting position after her fall is consistent with her body’s forward momentum during 2 to 3 stumbling steps in a failed recovery effort after a trip on the 1.25 inch raised section of flooring.” Her injuries documented in the autopsy report, forehead fractures, orbital trauma, and a Type II dens fracture in the C2 of her cervical spine, are “consistent with a trip leading to a forward fall and significant facial/forehead impact with the ground.” Published research using human cadavers “has assessed the biomechanical causes of C2 fractures similar to that sustained by Ms. Valencia.” “A combined loading pattern of horizontal shear and vertical compression loading is consistent with fracture of the C2 . . . . This type of compressive and shear loading is associated with a blow delivered to the head.” In a study testing cervical spines of cadavers, such fractures were sustained due to abrupt deceleration of the head and continued forward torso momentum. On the whole, Ms. Valencia’s diagnosed neck injuries are consistent with a face-first impact due to a loss of balance from a trip and forward fall. Ms. Valencia’s injury pattern is biomechanically inconsistent with a 11 backwards fall or sideways slip. “Given the totality of the known facts, the most likely biomechanical explanation for Ms. Valencia’s fall is that she tripped at the threshold transition area, which initiated a forward stumble into the hallway. The forward momentum from chasing the dog, stumbling steps in an unsuccessful effort to recover balance, and sliding on the ground after face/forward impact are consistent with Ms. Valencia’s described rest position near the end of the hallway” and with her “diagnosed injuries.” “Her injuries are not consistent with a slip or standing fall such as from a loss of balance due to dizziness.” “Had the threshold elevation been within safe limits or adequately marked, it is probable that Anya’s fall could have been prevented.” Dr. David Lahijaniha, a veterinarian and managing owner of an animal medical center with experience in veterinary medicine, hospital operations, regulatory compliance and industry best practices for veterinary hospitals and other animal care settings, behavioral assessments of dogs and cats, and safe handling techniques and physical restraints to prevent escape or injury, reviewed case-specific summary judgment documents and gave the following opinions. The failure to properly secure the animal by the veterinary staff, and the propped-open door of the grooming room created foreseeable hazards that were not adequately mitigated. Based on the photos and deposition testimony of Gee, the grooming room at Skyline Pet Hospital was not properly enclosed, and the door was deliberately propped open, violating industry best practices for veterinary facility safety. Secure enclosures are critical in veterinary settings to prevent animal escape and ensure a controlled environment for both staff and clients, and keeping doors closed is a fundamental safety measure that minimizes risks associated with unpredictable animal behavior. The failure to maintain a properly enclosed 12 animal grooming area created an entirely preventable hazard that directly contributed to the circumstances leading to Valencia’s fall. The veterinary staff failed to properly secure the animal when it was taken off its leash in the grooming room. Dr. Lahijanija stated, “Standard protocols require that animals be restrained using harnesses, tethers, or enclosed spaces to prevent escape and injury. In this case, no such precautions were taken by the Skyline staff, allowing the dog to escape from the room the moment it was unrestrained by its owner. This failure represented a significant deviation from accepted veterinary safety practices and exposed both staff and clients to foreseeable risks.” He went on to state, “It is well understood in veterinary medicine that an unrestrained dog may often attempt to flee, particularly in an unfamiliar and stressful environment. This makes it highly predictable that an unrestrained dog would run when given the opportunity, leading to staff, clients, or owners instinctively chasing it. This situation significantly increases the likelihood of injury, whether from tripping over obstacles, slipping on uneven surfaces, or colliding with the animal itself.” He further explained that clients should not be permitted in restricted staff only areas, as allowing them into these spaces compromises safety and increases injury risks as they are often unfamiliar with their surroundings and hidden dangers therein. Anya Valencia should not have been allowed in the grooming room as this area was on the second floor and designated exclusively for employees. Employee-only areas are not set up for public access and present an unfamiliar setting for patrons with potential hidden dangers therein. Allowing Anya to be brought to the employee-only area directly violated a specific lease provision. By failing to adhere to industry safety standards and disregarding their own policy against bringing clients to 13 the grooming room, Skyline Pet Hospital “created foreseeable hazards that were not adequately mitigated and resulted in the injury and death of Anya Valencia.” The trial court admitted portions of the declarations but sustained defendant’s objections to many of the experts’ opinions and foundational observations, which it labeled as “conjecture and speculation.” It granted defendants’ motion, stating that, “[W]ithout Plaintiffs’ experts’ inadmissible opinions regarding causation, a jury would be left with, at best, their opinions that the fatal fall was equally ‘consistent with’ Defendants’ alleged negligence.” II. DISCUSSION A. Legal Principles 1. Negligence and Premises Liability The essential elements of a negligence claim are duty, breach, causation and damages. (Ortega v. Kmart Corp. (2001) 26 Cal.4th 1200, 1205.) Premises liability has the same four elements. (Kesner v. Superior Court (2016) 1 Cal.5th 1132, 1158; Coyle v. Historic Mission Inn Corporation (2018) 24 Cal.App.5th 627, 634.) Defendants did not challenge plaintiffs’ ability to show defendants’ duty or breach of duty or plaintiffs’ damages. They argued only that plaintiffs could not establish causation. “Causation is established for purposes of California tort law if the defendant’s conduct is a ‘substantial factor’ in bringing about the plaintiff’s injury.” (Liberty Surplus Ins. Corp. v. Ledesma & Meyer Constr. Co. (2018) 5 Cal.5th 216, 223; see CACI No. 400.) “ ‘[A] substantial factor in causing harm is a factor that a reasonable person would consider to have contributed to the harm. It must be more than a remote or trivial factor. It does not have 14 to be the only cause of the harm.’ ” (Sobalvarro v. Vibra Health Care (2026) 119 Cal.App.5th 748, 762 (Sobalvarro), quoting CACI No. 430.) “[O]ur Supreme Court has explained that ‘ “[t]he substantial factor standard is a relatively broad one, requiring only that the contribution of the individual cause be more than negligible or theoretical.” ’ ” (Sobalvarro, at p. 763, quoting Bockrath v. Aldrich Chemical Co., Inc. (1999) 21 Cal.4th 71, 79 and Rutherford v. Owens-Illinois, Inc. (1997) 16 Cal.4th 953, 978.) “The substantial factor standard ‘subsumes’ and ‘generally produces the same results as does the “but for” rule of causation which states that a defendant’s conduct is a cause of the injury if the injury would not have occurred “but for” that conduct.’ [Citation.] And ‘ “[l]egal causation is generally a question of fact to be determined by the jury . . . unless, as a matter of law, the facts admit of only one conclusion.” ’ ” (Sobalvarro, supra, 119 Cal.App.5th at p. 763; State Dept. of State Hospitals v. Superior Court (2015) 61 Cal.4th 339, 353.) “ ‘ “[C]ausation . . . is ordinarily a question of fact which cannot be resolved by summary judgment. The issue of causation may be decided as a question of law only if, under undisputed facts, there is no room for a reasonable difference of opinion.” ’ ” (Zaragoza v. Adam (2025) 109 Cal.App.5th 113, 120.) 2. Summary Judgment “Summary judgment is no longer a disfavored procedure, but ‘is now seen as “a particularly suitable means to test the sufficiency” of the plaintiff's or defendant’s case.’ ” (Alameda Health System v. Alameda County Employees’ Retirement Assn. (2024) 100 Cal.App.5th 1159, 1174; see Perry v. Bakewell Hawthorne, LLC (2017) 2 Cal.5th 536, 542.) Nonetheless, because it deprives the losing party of the right to a jury trial, it is not granted lightly. 15  “[A]ny party to an action, whether plaintiff or defendant, ‘may move’ the court ‘for a summary judgment’ in his favor on a cause of action (i.e., claim) or defense (Code Civ. Proc., § 437c, subd. (a) . . . ).” (Aguilar v. Atlantic Richfield Co. (2001) 25 Cal.4th 826, 843 (Aguilar).) “A defendant moving for summary judgment “bears an initial burden of production to make a prima facie showing of the nonexistence of any triable issue of material fact; if he carries his burden of production, he causes a shift, and the opposing [plaintiff] is then subjected to a burden of production of his own to make a prima facie showing of the existence of a triable issue of material fact.” (Id. at p. 850.) A defendant who moves for summary judgment against a plaintiff must present evidence that would require a reasonable trier of fact to find the issue of fact tendered by plaintiff—here that defendants’ negligence caused Valencia’s injury—is not more likely than not. (Id. at p. 851.) Unlike many other aspects of a court’s job, its primary task in deciding a motion for summary judgment is not to resolve factual disputes but to determine whether they exist. (Binder v. Aetna Life Ins. Co. (1999) 75 Cal.App.4th 832, 839 [“primary function is to identify issues rather than to determine issues”].) The lens through which the court must view the evidence is different from that in other contexts. The court must strictly construe the moving party’s evidence. By contrast, it must liberally construe the opposing party’s evidence and resolve any evidentiary doubts or ambiguities in the opposing party’s favor. (Id. at p. 838; Nazir v. United Airlines, Inc. (2009) 178 Cal.App.4th 243, 253-254 (Nazir).) And it must draw all inferences that reasonably can be drawn in favor of the opposing party and consider the evidence, including inferences, in the light most favorable to the opposing party. (Weiss v. People ex rel. Dept. of Transportation (2020) 9 Cal.5th 840, 864 (Weiss); Nazir, at pp. 253-254.) This includes expert 16 witness declarations. (See Zaragoza v. Adam, supra, 109 Cal.App.5th at p. 121.) At no point is it appropriate for the court to weigh the evidence in the manner of a factfinder to determine whose version is more likely true or judge the credibility of the parties’ witnesses. (Aguilar, supra, 25 Cal.4th at p. 856 [agreeing that “court may not weigh the plaintiff’s evidence or inferences against the defendants’ as though it were sitting as the trier of fact”]; Weiss, supra, 9 Cal.5th at p. 864 [“Courts deciding motions for summary judgment or summary adjudication may not weigh the evidence but must instead view it in the light most favorable to the opposing party and draw all reasonable inferences in favor of that party”].) The question is not whether the trial court believes one party’s interpretation of the evidence is more plausible than the other’s; it is “what any evidence or inference could show or imply to a reasonable trier of fact.” (Aguilar, at p. 856.) The trial court “does not decide on any finding of its own, but simply decides what finding such a trier of fact could make for itself.” (Ibid.) “We review a grant of summary judgment de novo . . . “decid[ing] independently whether the facts not subject to triable dispute warrant judgment for the moving party as a matter of law.” (Intel Corp. v. Hamidi (2003) 30 Cal.4th 1342, 1348.) Further, “ ‘[w]e independently review the parties’ papers supporting and opposing the motion, using the same method of analysis as the trial court.’ ” (Apex Solutions, Inc. v. Falls Lake Ins. Management Co., Inc. (2024) 100 Cal.App.5th 1249, 1256.) “We consider all the evidence set forth in the moving and opposition papers except that to which objections were made and properly sustained by the trial court.” (South Lake Tahoe Property Owners Group v. City of South Lake Tahoe (2023) 92 Cal.App.5th 735, 745.) 17  3. Review of Evidentiary Rulings As a general matter, appellate courts review a trial court’s evidentiary rulings under an abuse of discretion standard. However, whether that standard applies to evidentiary rulings on summary motions has been the subject of some debate. 6 At minimum, we apply de novo review to any legal question presented by evidentiary rulings. (Sargon, supra, 55 Cal.4th 747, 773; see Strobel v. Johnson & Johnson, supra, 70 Cal.App.5th at p. 817 [Sanchez issues]; see also Garner v. BNSF Railway Co. (2024) 98 Cal.App.5th 660, 673 (Garner) [de novo review applies to evidentiary rulings that preclude an entire cause of action].) We need not decide the broader question of which standard of review applies in summary judgment proceedings because the trial court’s evidentiary rulings were erroneous under either standard. 4. Expert Testimony and Sargon At issue in this case are rulings excluding experts’ analyses and opinions about causation, which have effectively denied plaintiffs the 6 Sixteen years ago, our Supreme Court raised but did not decide the question whether on review of summary judgment rulings appellate courts should apply de novo review, “the general standard of review applicable to summary judgment rulings,” in reviewing a trial court’s evidentiary rulings. (See Reid, supra, 50 Cal.4th 512, 535.) Not long before that, we had observed, “[w]hether abuse of discretion is the proper standard of review when rulings on evidentiary objections are based on papers alone presents an interesting question, one that is by no means settled.” (Nazir, supra, 178 Cal.App.4th at p. 255, fn. 4.) We did not decide the question in Nazir because the trial court’s ruling sustaining all but one of the defendant’s 700- plus objections was plainly an abuse of discretion. (Id. at p. 255.) After Reid, in Pipitone v. Williams (2016) 244 Cal.App.4th 1437, 1450-1452, the Sixth District held de novo review applies to evidentiary rulings on summary judgment. The weight of authority among Court of Appeal decisions after Reid is that abuse of discretion applies. (Strobel v. Johnson & Johnson (2021) 70 Cal.App.5th 796, 816-817.) We reserve our view on the issue for such time as the parties in a case before us have briefed and argued it. 18 opportunity to present their case to a jury. The scope of admissibility for expert opinions is governed by Evidence Code sections 801 and 802. Section 801 limits expert opinion testimony to that which is “(a) [r]elated to a subject that is sufficiently beyond common experience that the opinion of an expert would assist the trier of fact; and (b) [b]ased on matter . . . that is of a type that reasonably may be relied upon by an expert in forming an opinion upon the subject to which [the] testimony relates . . . .” “[S]ection 802 provides [in relevant part] that ‘A witness testifying in the form of an opinion may state [on direct examination] . . . the reasons for his opinion and the matter [(including, in the case of an expert, his special knowledge, skill, experience, training, and education)] upon which it is based . . . ’ ” and “indicates the court may inquire into the expert’s reasons for an opinion.” (Sargon, supra, 55 Cal.4th at p. 771.) A court may inquire into the type of material on which the expert relies under section 801 “but also [under section 802] whether that material actually supports the expert’s reasoning. ‘A court may conclude that there is simply too great an analytical gap between the data and the opinion proffered.’ ” (Sargon, at p. 771.) In Sargon, our high court held that under Evidence Code sections 801 and 802, “the trial court acts as a gatekeeper to exclude expert opinion testimony that is (1) based on matter of a type on which an expert may not reasonably rely, (2) based on reasons unsupported by the material on which the expert relies, or (3) speculative.” (Sargon, supra, 55 Cal.4th at pp. 771- 772.) But the court was clear that the gatekeeping role is strictly bounded. “The trial court’s preliminary determination whether the expert opinion is founded on sound logic is not a decision on its persuasiveness. The court must not weigh an opinion’s probative value or substitute its own opinion for the expert’s opinion. Rather, the court must simply determine whether the 19 matter relied on can provide a reasonable basis for the opinion or whether that opinion is based on a leap of logic or conjecture.” (Id. at p. 772.) The court “does not resolve scientific controversies” but rather conducts a “ ‘circumscribed inquiry’ to ‘determine whether, as a matter of logic, the studies and other information cited by experts adequately support the conclusion that the expert’s general theory or technique is valid.’ ” (Ibid., quoting Imwinkelried & Faigman, Evidence Code Section 802: The Neglected Key to Rationalizing the California Law of Expert Testimony (2009) 42 Loyola L.A. L.Rev. 427, 449.) The goal is “simply to exclude ‘clearly invalid and unreliable’ expert opinion.” (Sargon, at p. 772.) Critically, the gatekeeper’s focus “ ‘ “must be solely on principles and methodology, not on the conclusions that they generate.” ’ ” (Garrett v. Howmedica Osteonics Corp. (2013) 214 Cal.App.4th 173, 186.) “Sargon should not be construed so broadly that the gatekeeper effectively supplants both the expert’s reasonable scientific judgment and the jury’s role. That would be at odds with Sargon’s emphasis on the limited role of the evidentiary gatekeeper. (Sargon, supra, 55 Cal.4th at p. 772.) In keeping the gate, it is not the trial court’s proper function to second-guess the judgment of a qualified expert who has provided a reasonable scientific explanation for his conclusions and used a scientifically accepted methodology for reaching them based on the available data, even if the data itself is inconclusive. ‘So long as an expert’s testimony rests upon “ ‘good grounds,’ based on what is known” [citation], it should be tested by the adversarial process, rather than excluded for fear that jurors will not be able to handle the scientific complexities.’ ” (Garner, supra, 98 Cal.App.5th at p. 679.) 20  B. Analysis 1. The Trial Court Misapplied Sargon and Erred in Excluding the Plaintiffs’ Expert Opinions. Defendants filed a 40-page document in the trial court raising objections to virtual