Marvin Carter II v. Bnsf Railway Company

IN THE ARIZONA COURT OF APPEALS DIVISION TWO MARVIN CARTER II, A SINGLE INDIVIDUAL, Plaintiff/Appellant/Cross-Appellee, v. BNSF RAILWAY COMPANY, A WHOLLY-OWNED SUBSIDIARY OF BURLINGTON NORTHERN SANTA FE CORPORATION, A DELAWARE CORPORATION, Defendant/Appellee/Cross-Appellant. No. 2 CA-CV 2025-0286 Filed November 3, 2026 Appeal from the Superior Court in Maricopa County No. CV2019014216 The Honorable Randall H. Warner, Judge AFFIRMED COUNSEL Breyer Law Offices P.C., Phoenix By Mark P. Breyer and Dennis O’Berry Counsel for Plaintiff/Appellant/Cross-Appellee  CARTER v. BNSF RY. CO. Opinion of the Court Womble Bond Dickinson LLP, Phoenix By Susan M. Freeman and Lauryn K. Johnson and Atkinson, Baker & Rodriguez P.C., Albuquerque, New Mexico By Justin D. Rodriguez and Julia E. McFall Counsel for Defendant/Appellee/Cross-Appellant OPINION Judge O’Neil authored the opinion of the Court, in which Presiding Judge Gard and Judge Eckerstrom concurred. O’ N E I L, Judge: Marvin Carter sued his employer, BNSF Railway Company, under the Federal Employers’ Liability Act (FELA). A jury found in favor of BNSF, and Carter appeals from the trial court’s resulting judgment. BNSF cross-appeals from the court’s denial of its motion for sanctions. FELA creates a federal claim for workplace injuries in the railroad industry. Butynski v. Springfield Terminal Ry. Co., 592 F.3d 272, 276 (1st Cir. 2010); see also 45 U.S.C. § 51. Both state and federal courts may hear these claims, 45 U.S.C. § 56, and although federal law governs them, cases heard in state courts are subject to state procedural rules, St. Louis Sw. Ry. Co. v. Dickerson, 470 U.S. 409, 411 (1985). BNSF’s cross-appeal asks whether sanctions under Rule 68, Ariz. R. Civ. P., are substantive and thus preempted by federal law. Carter primarily challenges the trial court’s evidentiary rulings. We affirm as to both the appeal and the cross-appeal. Background The morning of September 4, 2018, Carter, an engineer, reported to his worksite in Kingman to reposition and service two locomotives. At 7:19 a.m. local time, he told his trainmaster that locomotive 5440 had an oil leak. The oil had leaked onto the engineer’s catwalk, a walkway alongside the locomotive. Carter then walked through the oil while moving the 5440 to a repair spot. At 8:05 a.m. local time, he reported 2  CARTER v. BNSF RY. CO. Opinion of the Court that he had slipped and hurt his knee. Carter saw an orthopedic surgeon the next day and later had knee surgery. In October 2019, Carter sued BNSF under FELA alleging that BNSF’s negligence had caused his knee injury.1 After a seven-day trial, the jury returned a verdict for BNSF, and the trial court entered judgment against Carter. BNSF then sought sanctions under Rule 68(g), which the court denied. Carter appealed, and BNSF cross-appealed. Carter’s Appeal Carter raises multiple evidentiary issues on appeal. He asserts the trial court erred in allowing evidence of an improper theory that he had assumed the risk of injury. He also argues the court erred in admitting undisclosed and prejudicial evidence.2 The parties do not dispute that the Arizona Rules of Evidence apply to Carter’s evidentiary challenges. See Yauch v. S. Pac. Transp. Co., 198 Ariz. 394, ¶ 12 (App. 2000) (“[A] state’s rules of evidence are procedural rules that apply to and govern FELA cases brought in state court, so long as the evidentiary rule does not interfere with, lessen, or destroy a party’s federal substantive rights under the FELA.”); see also Padilla v. S. Pac. Transp. Co., 131 Ariz. 533, 534 (App. 1982). We review the court’s rulings on evidence and disclosure for an abuse of discretion. John C. Lincoln Hosp. & Health Corp. v. Maricopa County, 208 Ariz. 532, ¶ 33 (App. 2004); Link v. Pima County, 193 Ariz. 336, ¶ 3 (App. 1998). I. Assumption-of-Risk Defense Carter argues that BNSF’s “entire argument” improperly relied on his purported assumption of risk. He asserts there is “no question that BNSF was negligent,” so any negligence by Carter himself “must not result in a defense verdict” because assumption-of-risk defenses have long 1He also claimed that BNSF was strictly liable under the Locomotive Inspection Act. The trial court granted partial summary judgment in favor of BNSF on that claim, and we affirmed on appeal. See Carter v. BNSF Ry. Co., 258 Ariz. 48 (App. 2024). 2In his statement of issues, Carter also asserts the trial court abused its discretion in denying his motion for a new trial, but he then fails to develop the argument, waiving it. See Ritchie v. Krasner, 221 Ariz. 288, ¶ 62 (App. 2009). 3  CARTER v. BNSF RY. CO. Opinion of the Court been precluded in FELA cases. According to Carter, the trial court erred in allowing evidence that supported an impermissible defense. At common law, an employer could argue that an employee had assumed the risk of injury associated with the “known,” “ordinary,” or “plainly observable” dangers of his occupation. Schlemmer v. Buffalo, Rochester, & Pittsburgh Ry. Co., 220 U.S. 590, 596 (1911); see also Taylor v. Burlington N. R.R. Co., 787 F.2d 1309, 1316 (9th Cir. 1986) (“At common law an employee’s voluntary, knowledgeable acceptance of a dangerous condition that is necessary for him to perform his duties constitutes an assumption of risk.”). Carter is correct that such a defense is not available in FELA cases. 45 U.S.C. § 54; see also Ganotis v. N.Y. Cent. R.R. Co., 342 F.2d 767, 768 (6th Cir. 1965); Haines v. S. Pac. Co., 7 Ariz. App. 65, 72 (1968). FELA does, however, allow employers to raise contributory negligence as a defense. Butynski, 592 F.3d at 276; Taylor, 787 F.2d at 1314. Contributory negligence “is a careless act or omission on the plaintiff’s part tending to add new dangers to conditions that the employer negligently created or permitted to exist.” Taylor, 787 F.2d at 1316; see also Schlemmer, 220 U.S. at 596 (“Contributory negligence, on the other hand, is the omission of the employee to use those precautions for his own safety which ordinary prudence requires.”). Contributory negligence does not bar recovery, but it “operates to diminish the recovery in proportion to the parties’ comparative fault.” Butynski, 592 F.3d at 276; see also 45 U.S.C. § 53. At trial, BNSF asked Carter how many times he had walked through the oil before slipping. Carter said he had done so five times. When asked whether he could have avoided the oil, Carter testified that he had “avoided it the best [he] could.” He maintained that he had needed to walk through the oil to move the 5440 to the repair spot.3 3Although Carter did not object contemporaneously to this line of questioning, he did state on the record, before opening arguments, that BNSF’s theory that Carter had endangered himself by walking through the oil was an impermissible assumption-of-risk defense. The trial court rejected his argument, stating that the argument was “fairly within the concept of comparative fault.” We conclude Carter preserved his argument for appeal. See Padilla, 131 Ariz. at 535 (“Where an objection to a certain class of evidence is distinctly made and overruled, objection need not be repeated to the same class of evidence subsequently received, although the evidence is given by, or the questions asked of, another witness.”). 4  CARTER v. BNSF RY. CO. Opinion of the Court Carter suggests BNSF improperly elicited this testimony to argue that his failure to choose “a saf[]er pathway or method of performing his job” precluded his recovery. He compares BNSF’s theory to an improper assumption-of-risk argument in Panhandle & Santa Fe Railway Co. v. Howard, 397 S.W.2d 300 (Tex. Civ. App. 1965). In Panhandle, a railway employee sued his employer for a back injury he had suffered while lifting a gate. 397 S.W.2d at 301. Although the jury returned a verdict for the employee, it found that both parties shared fault because the employee had known the gate was defective. Id. The railway argued on appeal that the trial court should have instructed the jury to decide whether the employee, “knowing his own physical strength, abused such strength in choosing the way and means of closing the gate in question; and whether such act was negligence and a proximate cause of his injuries.” Id. The reviewing court affirmed the trial court’s refusal to provide that instruction because it pertained to the employee’s “state of mind” and thus amounted to a theory of assumption of risk. Id. at 302. Even accepting Panhandle’s characterization of assumption of risk as dependent on an employee’s “state of mind,” the evidence here supported a permissible defense of contributory negligence. This is true even if the same evidence might also have related to assumption of risk. See Haines, 7 Ariz. App. at 72 (“[W]here the evidence necessary to establish contributory negligence might also be used to establish assumption of risk, the defendant will not be precluded from offering such evidence.”). Like the Panhandle employee’s attempt to lift a gate with knowledge that it was defective, Carter’s decision to repeatedly walk through the oil was relevant to his own negligence regardless of any theory concerning assumption of risk. See 397 S.W.2d at 301-02. Indeed, BNSF presented evidence that Carter could have avoided the oil by exiting the locomotive from the staircase at the “nose” end. There was also evidence that Carter did not have to move the locomotive to the repair spot after finding the oil. In closing, BNSF argued that, if the jury found both parties at fault, Carter should bear most of the responsibility for “walking through the oil.” This is not the same as an argument that Carter’s assumption of risk should bar recovery, especially in light of the jury instructions. In particular, the trial court properly instructed the jury that Carter “is not negligent simply because he, at the request or direction of BNSF, worked at a dangerous job or in a dangerous place.” The jury was also instructed that “[n]egligence causes an injury if it played any part, no matter how slight, in bringing about the injury.” We presume jurors follow their instructions. Hyatt Regency Phx. Hotel Co. v. Winston & Strawn, 184 Ariz. 120, 140 (App. 5  CARTER v. BNSF RY. CO. Opinion of the Court 1995). Thus, the court did not abuse its discretion in allowing BNSF to present evidence that supported a defense of contributory negligence. To the extent Carter argues the evidence was insufficient to support the verdict for BNSF, he waives the argument by failing to develop it. See Ritchie v. Krasner, 221 Ariz. 288, ¶ 62 (App. 2009). Waiver aside, despite Carter’s contention to the contrary, BNSF presented evidence that it had adequately maintained the 5440 locomotive. It is not our role to reweigh this evidence on appeal. Teets v. Chicago, S. Shore & S. Bend R.R., 238 F.2d 223, 228 (7th Cir. 1956). Because we find no error, we do not reach Carter’s fundamental-error argument. II. Video Disclosure Format Carter asserts BNSF showed a video at trial in a different format than it had disclosed. During his direct examination, Carter testified that he had discovered and reported the oil leak after moving the 5440. On cross-examination, BNSF played a video from the 5440 locomotive, which the parties had stipulated to admit into evidence. The video included time stamps that showed the 5440 start moving at 14:25 Greenwich Mean Time, which would have been 7:25 a.m. in Kingman. The accuracy of these time stamps and the difference between time zones became a significant issue at trial. Carter confirmed that the video showed the 5440’s first movement of the day. He also testified that he had reported the oil at 7:19 a.m. Kingman time, which he noted would have been 9:18 Central Time. He disputed the video’s time stamps and maintained that he had found the oil after moving the locomotive. During a sidebar, Carter asked to publish a converted version of the video without time stamps. The trial court admitted the exhibit and allowed Carter to show it to the jury. The next day, outside the jury’s presence, Carter told the court that before trial, he had only received the converted version of the video and had not watched the original time-stamped video. BNSF, however, asserted it had sent the original files to Carter five years earlier, along with instructions for special software needed to view the video. Carter did not dispute this, but he asked BNSF to resend the files with viewing instructions. The court later allowed Carter to examine numerous witnesses about the accuracy of time stamps in locomotive videos. In closing, BNSF referenced the video to argue that Carter had moved the 5440 after discovering the oil. Carter continued to argue the time stamps were inaccurate. 6  CARTER v. BNSF RY. CO. Opinion of the Court On appeal, Carter argues a party must disclose “evidence in a way that it can be viewed.” But, as he acknowledged at trial, his counsel had received the original files in 2020 with an explanation of the required software needed to view the video. To the extent he suggests a party cannot rely on digital evidence with particular software requirements, he waives the argument by failing to support it with authority.4 See Ritchie, 221 Ariz. 288, ¶ 62. Carter also suggests the trial court erred in permitting inaccurate references to time zones, pointing to his own testimony that Kingman time was two hours different from Central. He asserts that BNSF offered a timeline in closing that “amplified” the errors and confused the jury. After Carter’s testimony about time zones, his counsel stated during a sidebar that Kingman and Central were “one hour different, not two.” With the parties’ agreement, the trial court instructed the jury about how local time in Kingman relates to Greenwich Mean Time. In his closing argument, Carter acknowledged that “Greenwich Mean Time is UTC minus zero, Central Daylight Time is UTC minus 5, Central Standard Time is UTC minus 6 and Mountain Standard Time is UTC minus 7,” but he argued that he reported the oil at “8:19 Mountain.” To the extent the time zones were confusing, Carter contributed to that confusion with testimony that was inconsistent with his argument. Indeed, he told the jury in closing that he could not make sense of the timeline and asked the jury to do so. The timing of Carter’s report was relevant to BNSF’s theory that Carter had been negligent in moving the 5440 after finding the oil leak. The trial court did not abuse its discretion in permitting this testimony and argument. See Ariz. R. Evid. 402, 403. Carter also asserts the trial court “codified those errors” by instructing the jury on facts concerning time zones. But Carter did not 4In his reply brief, Carter asserts the video presented an issue of “fundamental unfairness” because it “robbed [him] of the opportunity to truly explore the break in time contained within.” He waives this argument by failing to meaningfully develop it with citations to legal authority. See Ritchie, 221 Ariz. 288, ¶ 62. Waiver aside, Carter acknowledged during a sidebar at trial that the time stamps in the original video reflected a fifteen-minute gap of time, and BNSF’s director of locomotives and air brake systems testified why these breaks in time occur. 7  CARTER v. BNSF RY. CO. Opinion of the Court object to that instruction, waiving his argument. See Trantor v. Fredrikson, 179 Ariz. 299, 300 (1994). Again, finding no error, we do not reach Carter’s argument that the purported error was fundamental. III. Prejudicial Evidence Carter argues the trial court erred under Rule 403 in “allowing [u]nduly [p]rejudicial [e]vidence,” including an anonymous tip, a reference to his employment probation status, and an allegation of perjury.5 A court “may exclude relevant evidence if its probative value is substantially outweighed by a danger of . . . unfair prejudice.” Ariz. R. Evid. 403. A. Anonymous letter Before trial, Carter moved to preclude an anonymous letter BNSF had received, which stated: “Marvin Carter did not get hurt at work! He got hurt at a trampoline park in Las Vegas on the day before.” Carter asserted that the content of the letter was “inadmissible hearsay” and that it should be precluded under Rule 403. The trial court denied Carter’s motion, reasoning that the letter was not hearsay if offered to explain why BNSF later began investigating whether Carter’s injury really happened at work. But the court later reconsidered and concluded that the prejudicial nature of the letter substantially outweighed its probative value. The court thus precluded BNSF from admitting or using the letter or showing it to the jury. The court did, however, allow BNSF to explain that it had “received an anonymous communication that [Carter had] injured himself before the incident in question at a trampoline park.” At trial, BNSF asked its superintendent of operations “what made [him] call into question” the source of Carter’s injury. Over Carter’s objection, the superintendent stated that he had “received an anonymous tip that Mr. Carter had injured himself at a trampoline park and not at work.” BNSF’s medical expert later testified that, based on his review of Carter’s medical records, Carter had “tweaked his knee or allegedly had a misstep in an oil slick or from a trampoline event” and at most sustained a 5Carter asserts that these three “examples” “[c]ollectively . . . provide overwhelming evidence of the fundamental errors leading to undue prejudice.” We do not address this argument because as we explain below, there was no error; regardless, we note that our supreme court has acknowledged a limited application of the cumulative error doctrine in only the criminal context. See State v. Pandeli, 242 Ariz. 175, ¶ 69 (2017). 8  CARTER v. BNSF RY. CO. Opinion of the Court non-structural, non-verifiable knee sprain or strain. He explained that whether Carter’s knee issues stemmed from oil or a trampoline was “irrelevant” to his opinion, which relied only on imaging from an X-ray and MRI of Carter’s knee. While cross-examining the expert, Carter asked numerous questions about his reliance on the tip and failure to independently verify it, which resulted in the trial court’s decision to allow BNSF to show the letter to the jury and ask “limited questions” about it. On appeal, Carter maintains that the letter’s contents were “clearly hearsay.” And he argues the trial court erred in “allowing the presentation of [the] anonymous letter,” because it was admitted “for the purpose of painting [him] a liar.” His opening brief does not plainly state whether he intends to challenge the court’s pretrial ruling allowing testimony about the tip without admitting the written letter, its subsequent decision to allow the jury to see the letter itself after concluding Carter had “opened the door,” or both. Either way, there is little substantive difference between the testimony describing the tip and the contents of the letter, and Carter raised the same hearsay and prejudice objections to the letter and its contents both before and during trial. The objections are not trivial, as the court acknowledged, especially because the purported non-hearsay basis for introducing the tip—explaining the reason for BNSF’s investigation— was not meaningfully disputed at trial. But we need not decide whether the court erred in permitting evidence of the tip. To the extent the tip might have been prejudicial in isolation, the prejudice was in its tendency to suggest Carter was injured at a trampoline park. That effect, however, was negligible in the context of this trial and did not affect Carter’s substantial rights. See Ariz. R. Civ. P. 61 (harmless errors do not warrant disturbing judgment). BNSF presented significant evidence at trial to support its theory that Carter injured his knee at a trampoline park in Las Vegas.6 Carter acknowledged that he had visited the park with his family three days before his claimed workplace injury. A little over an hour after entering the park, Carter began texting his mother to ask for the name of the orthopedic surgeon who had performed surgery on Carter’s injured knee in 2004. Minutes later, records from Carter’s cellular provider then showed a 6Carter appears to take issue with the “trampoline line of questioning,” but he does not meaningfully develop an argument that the trial court erred in allowing it. To the extent his opening brief suggests an error, the argument is waived. See Ritchie, 221 Ariz. 288, ¶ 62. 9  CARTER v. BNSF RY. CO. Opinion of the Court 26-second call from his phone to the surgeon’s office. Carter claimed the call was placed accidentally by one of his children, while using Carter’s phone to look up the surgeon’s name after listening to a story about his recovery from surgery in the hospital. He testified his mother did not text him the name of the surgeon, and he had no explanation for the timing of the call after the text messages he had sent to his mother. Evidence suggesting Carter had suffered his injury at the trampoline park was a key feature of BNSF’s case at trial. The anonymous tip was not. Consistent with the pretrial ruling, BNSF’s superintendent mentioned the tip only briefly to explain that it was relevant to BNSF’s investigation of the workplace injury claim. And despite the presentation of the letter during the testimony of its medical expert, BNSF did not argue that the letter proved the source of Carter’s injury. Rather, BNSF merely asked the expert how he had relied on the letter, and he stated that he did not. Neither Carter nor BNSF referenced the letter during closing arguments. Given the far greater significance of the other evidence that Carter was injured at the trampoline park and the limited role the anonymous letter played at trial, Carter has not shown the presentation of the letter affected the outcome of the trial. Any error, even if we were to find one, was harmless and would not warrant reversal. See Ariz. R. Civ. P. 61; see also Paz v. City of Tucson, 256 Ariz. 391, ¶ 15 (App. 2023) (reversal not warranted where appellant cannot show any claimed error affected outcome of case). B. Probation status In November 2018, BNSF investigated Carter for conduct that had occurred before September 4, 2018. BNSF found Carter responsible for multiple violations and fired him. Carter successfully appealed and was reinstated in August 2021. Before trial, Carter moved to exclude evidence of his disciplinary history at work, arguing that it was irrelevant and unfairly prejudicial. BNSF countered that the disciplinary process Carter likely anticipated in the weeks leading up to the incident gave him a motive to falsely claim a workplace injury. The trial court ruled that BNSF could “introduce evidence that [Carter] was on probation and subject to potential termination” at the time of his injury, but it precluded evidence of the reason for Carter’s probationary status. 10  CARTER v. BNSF RY. CO. Opinion of the Court At trial, BNSF questioned its superintendent of operations as to whether he had known about “Carter’s disciplinary status” on the date of the incident. Over an objection, the superintendent answered yes. BNSF then asked about the superintendent’s “understanding of [Carter’s] status.” The superintendent explained that Carter had been on “active Level S” status at the time, which he described as “when an employee commits a serious rules violation that could cause injury to themselves or others or damage the equipment.” On appeal, Carter argues the testimony about “Level S” probation violated the trial court’s pretrial ruling, had “little to no probative value,” and unfairly prejudiced him. It is debatable on this record whether the testimony exceeded the scope of what the court had intended to allow. Regardless, a court has inherent authority over the enforcement of its own rulings.7 Cf. Green v. Lisa Frank, Inc., 221 Ariz. 138, ¶¶ 29, 37-38 (App. 2009) (describing court’s authority to impose sanctions when party fails to comply with its orders). The court here chose to exercise that authority by intervening sua sponte during the testimony about Carter’s probation status, warning that the testimony had begun to reach “beyond the scope of the question.” Moreover, the testimony was probative as to BNSF’s theory that Carter had a motive to falsify an injury claim, and Carter does not adequately explain how that probative value was substantially outweighed by the danger of unfair prejudice. See Ariz. R. Evid. 403, 404(b)(2). The court did not abuse its discretion. See Gemstar Ltd. v. Ernst & Young, 185 Ariz. 493, 506 (1996). C. Perjury Over Carter’s objection, BNSF asked him the following question: “[O]n February 6, 2023, you perjured yourself in the Superior Court of the State of Arizona in the County of Mohave before the Honorable Kenneth L. Gregory; correct?” Carter said no, and the line of questioning ceased. Carter challenges this question on appeal. He argues the question was unsupported by evidence, prejudicial, and not probative. 7To the extent Carter also attempts to challenge the trial court’s pretrial ruling concerning his probation status, he waives that argument by failing to develop it. See Ritchie, 221 Ariz. 288, ¶ 62. Carter also challenges the admission of an “investigative letter,” but he waives this argument by failing to support it with citations to the record. See id.; see also Ariz. R. Civ. App. P. 13(a)(7)(B). 11  CARTER v. BNSF RY. CO. Opinion of the Court We reject Carter’s contention that the question was not probative. It was plainly “probative of [Carter’s] character for truthfulness.” Ariz. R. Evid. 608(b). And Carter’s argument that the question was unsupported by evidence ignores that extrinsic evidence to prove this specific instance of conduct would have been inadmissible.8 See id. Lawyers may generally ask relevant questions when there is a nonfrivolous, good-faith basis for doing so. Ariz. R. Sup. Ct. 42, ER 3.1; see also Ruth v. Rhodes, 66 Ariz. 129, 136 (1947) (“cross-examination by insinuation” is impermissible). Carter did not suggest at trial that BNSF lacked such a basis. To the contrary, he acknowledged that the Mohave County court had made the perjury finding, and he explained to the trial court the basis and context for that finding. To the extent Carter asserts prejudice because the jury did not hear a complete explanation about the perjury finding that he testified did not occur, Carter chose not to provide that explanation during his testimony on redirect. As it happened, the only evidence the jury heard was Carter’s statement that he had not perjured himself. The court did not abuse its discretion under Rule 403. BNSF’s Cross-Appeal State courts hearing FELA claims must apply federal substantive law. Monessen Sw. Ry. Co. v. Morgan, 486 U.S. 330, 335 (1988). FELA and United States Supreme Court’s decisions interpreting it are “absolutely binding on every state court.” S. Pac. Co. v. Gastelum, 38 Ariz. 127, 134 (1931). State procedural rules apply only if they do not interfere with, lessen, or destroy a federal right under FELA. Padilla, 131 Ariz. at 534. A procedural rule is one that provides the “judicial process for enforcing rights and duties recognized by substantive law and for justly administering remedy and redress for disregard or infraction of them.” Hanna v. Plumer, 380 U.S. 460, 461, 464 (1965) (considering whether service of process should be made under federal or state law where district court has diversity jurisdiction). In December 2021, BNSF made an offer of judgment, offering to pay a “lump sum” in exchange for Carter agreeing to “discharge” it from “all claims that were or could have been alleged” in the case. BNSF made a second offer in April 2022 and a third in January 2023. After the jury 8In his reply brief, Carter incorrectly argues that the question itself amounted to improper extrinsic evidence. We do not otherwise address this argument raised for the first time in the reply. See Nelson v. Rice, 198 Ariz. 563, n.3 (App. 2000). 12  CARTER v. BNSF RY. CO. Opinion of the Court entered a verdict in its favor, BNSF sought sanctions under both the version of Rule 68 in effect at the time of its first offer and under the current version of the rule. Carter objected, asserting in part that federal substantive law preempts state substantive law in FELA actions. In reply, BNSF argued that “Rule 68 is procedural” because it is determined after “judgment is entered.” The trial court partially relied on Boyd v. BNSF Railway Co., 874 N.W.2d 234 (Minn. 2016), to reach the conclusion that Rule 68 is substantive rather than procedural, and it denied sanctions. BNSF maintains on appeal that sanctions pursuant to Rule 68 are procedural and thus not preempted by FELA. Federal preemption is an issue of law that we review de novo. Hill v. Peterson, 201 Ariz. 363, ¶¶ 1, 5 (App. 2001) (determining whether National Labor Relations Act preempted state law claim); Alby v. BNSF Ry. Co., 934 N.W.2d 831, 832-33 (Minn. 2019) (whether state or federal rule applies in FELA action is question of law subject to de novo review). In Boyd, the state rule at issue imposed “additional costs on a defendant who refuses a plaintiff’s settlement offer” if the judgment ultimately obtained was less favorable to the defendant than the rejected offer. 874 N.W.2d at 239. The Minnesota Supreme Court determined the rule was substantive and preempted because to conclude otherwise would have “create[d] a disparity in FELA cases based solely on whether the plaintiff’s claim is brought in federal or state court.” Id. at 240, 242. It noted that this conclusion was “consistent with the congressional intent of encouraging uniformity between federal and state court FELA cases.” Id. at 240. BNSF argues that Boyd misapplied the “conceptual requirement that FELA claims be adjudicated uniformly.” It argues that, although the relief available under FELA must be uniform, this “does not require disregard for state post-judgment procedures.” BNSF further asserts that sanctions are procedural because they are comparable to postjudgment interest and other “post-judgment monetary procedures” applied after “the substantive rights created by FELA are fulfilled.” BNSF points to case law concluding that prejudgment interest is substantive, while postjudgment monetary adjustments are procedural. Compare Monessen Sw. Ry. Co., 486 U.S. at 336 (prejudgment interest), with Louisville & Nash. R.R. Co. v. Stewart, 241 U.S. 261, 263 (1916) (postjudgment penalty), and Alby, 934 N.W.2d at 834 (postjudgment interest). That framing overly focuses on the timing of the monetary consequence either before or after judgment. Whether a rule is substantive or procedural depends on whether it affects the parties’ substantive FELA 13  CARTER v. BNSF RY. CO. Opinion of the Court rights or merely regulates the process for their enforcement. See Padilla, 131 Ariz. at 534. Although the line between substance and procedure is not always clear, St. Louis Sw. Ry. Co., 470 U.S. at 411, damages are substantive, Monessen Sw. Ry. Co., 486 U.S. at 335. Prejudgment interest is also substantive, not because of its prejudgment nature, but because it is “designed to make the plaintiff whole and is part of the actual damages sought to be recovered.” Monessen Sw. Ry. Co., 486 U.S. at 335-36. In contrast, state rules have been treated as procedural when they control postjudgment processes that do not alter a party’s recovery. See Louisville & N.R. Co., 241 U.S. at 263; Alby, 934 N.W.2d at 832, 834-35. One such rule, for example, has provided that where a party posts a supersedeas bond to suspend the judgment during an appeal, that party must pay “10 per cent the cost of it to all persons if the judgment is affirmed.” Louisville & N.R. Co., 241 U.S. at 263. In approving the state court’s application of this rule, the United States Supreme Court explained that the court had “no obligation . . . to provide for a suspension of the judgment” and, absent the appeal, “interest would run as of course until the judgment was paid.” Id. In other words, the state rule served to enforce the prevailing party’s recovery as established in the judgment and did not redefine the nature and extent of that recovery. We conclude Rule 68 sanctions are “too substantial a part of a [party’s] potential liability” to be classified as a procedural rule. Monessen Sw. Ry. Co., 486 U.S. at 336; cf. Norfolk & W. Ry. Co. v. Liepelt, 444 U.S. 490, 495 (1980) (explaining that, for attorney fees to be awarded to successful litigant in FELA action filed in state court, federal law must provide for them); Newman v. Select Specialty Hosp.-Ariz., Inc., 239 Ariz. 558, ¶¶ 18-20 (App. 2016) (in discussion of retroactive application of statute providing for attorney fees, concluding that “right to an award of attorney fees is a substantive right”). Rule 68(g)(1) requires that “[a] party who rejects an offer, but does not obtain a more favorable judgment, . . . pay as a sanction-twenty percent of the difference between the amount of the offer and the amount of the final judgment.”9 The effect of this rule can 9Under the prior version of the rule, in effect at the time of BNSF’s first offer in December 2021, the amount of a sanction was determined by the “offeror’s reasonable expert witness fees and double the taxable costs . . . incurred after the offer date,” in addition to “prejudgment interest on unliquidated claims accruing from the offer date.” Ariz. Sup. Ct. Order R-21-0011 (Aug. 30, 2021). 14  CARTER v. BNSF RY. CO. Opinion of the Court significantly alter the recovery available under FELA. For example, if the jury here had found in Carter’s favor but awarded damages totaling less than BNSF’s offer, the Rule 68 sanctions would have reduced Carter’s total recovery. See Ariz. R. Civ. P. 68(g)(1). Therefore, the trial court correctly determined that Rule 68 sanctions are substantive and thus preempted by federal law.10 Given our conclusion, we need not address the possibility of double recovery under both the prior and current versions of Rule 68. Disposition We affirm. We award no costs under A.R.S. § 12-341 because neither party has entirely prevailed on appeal. See In re V.L., 258 Ariz. 391, ¶ 27 (App. 2024). Carter is also not entitled to costs under A.R.S. § 12-342. 10Given that the trial court did not impose sanctions, we need not reach the question of whether FELA authorizes analogous sanctions. See Monessen Sw. Ry. Co., 486 U.S. at 336-37 (reaching issue of whether federal law authorizes prejudgment interest in case where trial court imposed prejudgment interest pursuant to state law). Moreover, BNSF does not argue that the court could have imposed sanctions pursuant to federal law. 15