United States v. Steven Chun

USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 1 of 32 FOR PUBLICATION In the United States Court of Appeals For the Eleventh Circuit ____________________ No. 22-14192 ____________________ UNITED STATES OF AMERICA, Plaintiff-Appellee, versus STEVEN CHUN, DANIEL TONDRE, Defendants-Appellants. ____________________ Appeal from the United States District Court for the Middle District of Florida D.C. Docket No. 8:20-cr-00120-WFJ-JSS-1 ____________________ Before NEWSOM, BRASHER, and TJOFLAT, Circuit Judges. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 2 of 32 2 Opinion of the Court 22-14192 TJOFLAT, Circuit Judge: BACKGROUND In United States v. Simon, 12 F.4th 1 (1st Cir. 2021), the First Circuit affirmed the convictions of the founder and four executives of Insys Therapeutics, Inc. (“Insys”), 1 under the Racketeer Influ- enced and Corrupt Organizations Act (“RICO”), 18 U.S.C. § 1962(d), 2 for conspiring to bribe physicians to prescribe Subsys, a fentanyl-laced spray medication administered beneath the tongue. Insys developed, and the U.S. Food and Drug Administration (“FDA”) approved, Subsys in early 2012 for use in the treatment of breakthrough cancer pain. 3 The “icing on the cake” of the bribery scheme was the “speaker program,” id. at 17, in which Insys paid selected physicians—in particular those specializing in pain medi- cine and prescribing Subsys off-label—hefty honoraria to speak at dinner meetings Insys’ representatives hosted. The purpose of 1 Insys was a publicly held pharmaceutical firm. Simon, 12 F.4th at 15. 2 The defendants were also found guilty of mail fraud and wire fraud, which constituted the predicate acts underlying the RICO offense. Four of the de- fendants were found guilty of honest services mail and wire fraud. Those acts also constituted predicate acts. 3 The term ‘‘breakthrough cancer pain’’ is a term of art: it refers to brief spikes in pain (typically lasting less than one hour) in patients with cancer who are already dealing with constant and relatively steady pain. All other uses of Sub- sys were deemed ‘‘off-label.’’ Simon, 12 F.4th at 15. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 3 of 32 22-14192 Opinion of the Court 3 these speaker programs was ostensibly to introduce Subsys to phy- sicians in the community, but their true purpose was to put cash in the hands of the prescribing physicians. Michael Babich, Insys’ President and Chief Executive Of- ficer, and Alec Burlakoff, Insys’ Vice President of Sales, pleaded guilty to the RICO conspiracy 4 and testified as prosecution wit- nesses at the trial. Burlakoff referred to the speakers, including Dr. Steven Chun, an appellant here, as “whales”: physicians who “had agreed in a very clear and con- cise manner that they were up for the deal, which meant that they would be compensated based on the number of prescriptions of Subsys they wrote. A cor- ollary to that deal was that “the more they wrote and the more they increased the dose, the more they’d get paid to speak.” At Burlakoff’s urging, regional sales managers were to have a “candid conversation” with each potential whale and make clear that if the physi- cian was going to receive payments from Insys, he was “going to write a significant amount of Subsys prescriptions to new patients as well as increase the doses of current patients.” Burlakoff told sales man- agers to view speakers as their “business partners.” 4 Burlakoff pleaded guilty to the RICO conspiracy. On January 23, 2020, the District Court sentenced him to 26 months in prison and a three years of su- pervised release. USA v. Babich et al., 1:16-cr-10343, ECF No. 1313 (D. Mass. Jan. 10, 2019). USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 4 of 32 4 Opinion of the Court 22-14192 Id. at 18 (alterations adopted). As for the speaker program, Burla- koff had this to say: [T]he speaking events themselves had little to no at- tendance. Often, only the speaker, a friend or family member, and the sales representative were on hand. Even when more people were in attendance, the speaker programs were mostly “social outings” or “just a reason to gather people and have dinner and pay [the doctor].” Although sales representatives were required to submit sign-in forms and attendee evaluation forms to a third-party compliance firm (Sci Medica), they frequently submitted inaccurate docu- mentation, including sign-in sheets with names and signatures of people who were not present, to give the speaking programs an aura of legitimacy. Id. at 19. The dinners were obvious shams. They were created to hide the fact that the honoraria Insys paid the speakers violated the “Anti-Kickback Statute,” 42 U.S.C. § 1320a-7b(b), which prohibits the payment or receipt of kickbacks in connection with a federal healthcare program, such as Medicare. The jury returned verdicts against the founder of Insys and four of its executives on May 2, 2019. USA v. Babich et al., 1:16-cr- 10343, ECF No. 841 (D. Mass. Jan. 10, 2019). This brings us to the case at hand. * * * On March 12, 2020, a Middle District of Florida grand jury returned an indictment against Steven Chun and Daniel Tondre. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 5 of 32 22-14192 Opinion of the Court 5 The grand jury superseded the indictment on February 5, 2022— 34 months later. The superseded version charged the defendants with committing 16 separate offenses, all based on the bribery scheme involved in Simon. Count One alleged that, from August 2012 through July 2015, six individuals conspired in violation of 18 U.S.C. § 371 to vi- olate the Anti-Kickback Statute by soliciting or receiving bribes for prescribing Subsys. Those six individuals were (1) Chun, a physi- cian specializing in pain medicine and an enrolled Medicare pro- vider; (2) Tondre, a sales representative and trainer for Insys whose sales territory included Chun and his medical practice; (3) Babich, Insys’ President and Chief Executive Officer; (4) Burlakoff, Insys’ Vice President of Sales; (5) Liz Gurrieri, an Insys technician; and (6) Pharmacist 1, who filled Chun’s prescriptions. Counts Two through Six alleged that, between May 4 and June 22, 2015, Tondre violated the Anti-Kickback Statute by paying Chun a bribe for prescribing Subsys. Counts Seven through Eleven alleged that Chun violated the Anti-Kickback Statute by accepting payments for writing Subsys prescriptions. Counts Twelve through Sixteen alleged that Chun on two occasions and Tondre on five committed identification fraud—using without authority the identification of another—between April 4 and June 16, 2015, in violation of 18 U.S.C. § 1028(a)(7). USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 6 of 32 6 Opinion of the Court 22-14192 Chun and Tondre entered pleas of not guilty to both indict- ments and stood trial before a jury on May 9, 2022. 5 The Govern- ment rested its case on May 19, and Chun did likewise. Tondre chose to testify at trial. At the close of the evidence, the defendants moved the District Court for judgment of acquittal. 6 The Court de- nied their motions. The jury found Chun guilty on Counts One and Seven through Eleven and Tondre guilty on Counts One through Six, Twelve, and Sixteen. Following the District Court’s imposition of their sentences,7 Chun and Tondre appealed their convictions and sentences. Both Chun and Tondre challenge the District Court’s denial of the motions for judgment of acquittal. We discuss the Court’s ruling in Part I. In Part II, we consider the District Court’s handling of two notes the jury submitted to the Court during deliberations. 5 On the eve of trial, the District Court, on the Government’s motion, dis- missed Counts Thirteen though Fifteen pending against Chun and Tondre. 6 See Fed. R. Crim. P. 29(a). On May 23, the Court granted Chun’s motion as to Counts Twelve and Sixteen. 7 After denying Chun’s Rule 29(c) and Rule 53 alternative motions for judg- ment as a matter of law and for a new trial, the District Court sentenced Chun on December 5, 2022, to concurrent prison terms of 42 months on the six counts of conviction and a three-year term of supervised release. On Decem- ber 15, 2022, the District Court sentenced Tondre to concurrent prison terms of 48 months on the eight counts of conviction and a three-year term of super- vised release. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 7 of 32 22-14192 Opinion of the Court 7 Part III addresses an issue involving Chun’s sentence. Part IV con- cludes, finding no basis for disturbing the District Court’s judg- ments, and therefore affirms. I. MOTIONS FOR JUDGMENT OF ACQUITTAL We must preface the Part I discussion with an explanation of how the Government chose to try this case. It treated the trial as an extension of the trial in Simon except that the Simon defendants would not be standing in the dock, and the trial would be held in Tampa, Florida, not in Boston, Massachusetts. But the Govern- ment’s star witnesses, Babich and Burlakoff, would be the same. They had been charged as RICO conspirators in Simon and having pleaded guilty, testified at the trial of their co-conspirators. And they had been charged as Count One conspirators here, although not indicted, and, as in Simon, testified at the trial of two of their co-conspirators, repeating much of what they testified to in Simon. And the time frames of the Simon conspiracy and the Count One conspiracy are the same, August 2012 through July 2015. So, although the jury would not know about Simon, it would learn that Babich and Burlakoff had pleaded guilty to criminal con- duct that occurred while they were at Insys, a conspiracy involving themselves and four Insys executives—John Kapoor, Joe Rowan, Sunrise Lee, and Mike Curry—that occurred during the time frame of the conspiracy alleged in Count One. The jury would also learn of the price they paid for their criminal conduct. Babich testified that he made $60 million exercising Insys stock options. Burlakoff had this to say: “It was all taken. . . . I owe 59 million in restitution.” USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 8 of 32 8 Opinion of the Court 22-14192 Asked if it was “joint and several with anyone else, he said, “[with] Mike Babich and John Kapoor.” * * * We now discuss whether the court erred in denying Chun and Tondre’s motion for judgments of acquittal. The questions this part poses are whether the evidence was sufficient to convict Chun8 on Count One and on Counts Seven through Eleven. We answer those questions by reviewing the evidence de novo count by count, considering it in the light most favorable to the Govern- ment and drawing all reasonable inferences and credibility choices in favor of the jury’s verdicts. United States v. Trujillo, 146 F.3d 838, 845 (11th Cir. 1998). Evidence is sufficient to sustain a conviction if any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt. United States v. Starr, 159 F.4th 901, 910 (11th Cir. 2025) (citing Cavazos v. Smith, 565 U.S. 1, 7, 132 S. Ct. 2, 6 (2011)). The guilty verdict need not be inevitable based on the evidence presented at trial; it need only be reasonable. United States v. Browne, 505 F.3d 1229, 1253 (11th Cir. 2007). We begin our review with the Count One conspiracy. 8 Tondre makes largely the same insufficiency argument as Chun, so we refer to them collectively as “Chun” in sections A and B—unless otherwise stated. Tondre makes a separate safe harbor provision argument, which we address individually in section C. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 9 of 32 22-14192 Opinion of the Court 9 A. Conspiracy Count We begin with the first count, that Chun conspired to vio- late the Anti-Kickback Statute. The elements of conspiracy are “(1) an agreement among two or more persons to achieve an un- lawful objective; (2) knowing and voluntary participation in the agreement; and (3) an overt act by a conspirator in furtherance of the agreement.” United States v. Hasson, 333 F.3d 1264, 1270 (11th Cir. 2003). An agreement is rarely, if ever, established by direct ev- idence. Rather it is usually shown by circumstantial evidence. United States v. Pulido, 133 F.4th 1256, 1276–77 (11th Cir. 2025). What the Government must prove is “the existence of an agreement to achieve an unlawful objective and the defendant’s knowing par- ticipation in that agreement.” United States v. Chandler, 388 F.3d 796, 806 (11th Cir. 2004). As discussed, Count One alleged that, from August 2012 through July 2015, Chun was a member of a conspiracy consisting of himself, Insys, Babich, Burlakoff, Tondre, Gurrieri, and Pharma- cist 1. The conspirators’ objective was to violate the Anti-Kickback Statute by paying physicians to prescribe Subsys. The first question we must ask is whether the evidence presented at trial established an agreement to violate the Anti-Kickback Statute. If so, we must then ask whether the evidence showed that Chun was a party to the agreement at some point in time and that one of the parties to the agreement committed an overt act in furtherance of the agree- ment’s objective. To answer the first question, we go back in time, to Insys’ organization and the development of the scheme where USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 10 of 32 10 Opinion of the Court 22-14192 Insys paid physicians to prescribe Subsys to their patients. Babich and Burlakoff take us there. Babich came on the scene before Subsys became a reality. Insys was a privately held corporation. John Kapoor founded it in 2004. He hired Babich, a banker, in 2009. At the time, Insys’ scien- tists were in the process of developing drugs and putting them through clinical trials in anticipation of FDA’s eventual approval of the drugs for distribution. The clinical trial of Subsys concluded in 2011, and, in January 2012, the FDA approved Subsys as a treat- ment for “breakthrough cancer pain”— “the spikes of pain that pa- tients experience when they have cancer.” With Subsys’ approval in hand, Kapoor appointed Babich as the company’s Chief Execu- tive Officer. At this point, Insys’ executives “were getting ready to launch Subsys itself, meaning sell[ing] it across the United States.” And Ba- bich was “prepar[ing] the company for [an] initial public offering,” going to New York, and trying to raise money, with the hope that Insys would “be on one of the stock exchanges.” The Subsys marketing program in the first six months of 2012 was not successful. As Babich expressed it, “we were not bringing in as much revenue of the drug as possible that we thought we could, patients were starting on too low of doses and dropping off, and we had many sales reps who weren’t getting . . . more than one script per month.” To generate more prescriptions, they launched a speaker program in mid-2012 as a pilot project. By the fall of 2012, the project was well underway nationwide. The USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 11 of 32 22-14192 Opinion of the Court 11 program focused on the high prescribing doctors. Insys’ “greatest chance at success” was getting the top doctors to use its product because they were already prescribing large volumes of other rapid onset fentanyl prescriptions. Babich opined that the speaker program was a “legitimate marketing strategy.” He explained: As a legitimate marketing strategy it’s commonplace for companies to have a physician educate other phy- sicians in their area about their experiences with the product itself. Usually you might have seen them when you go to dinner sometimes, there will be a pri- vate dining room and people in suits or nice dresses having dinner, and if it looks like a doctor or someone speaking, that’s usually a speaker program. So by de- sign that’s the way that they’re supposed to go. Some of Insys’ sales representatives and physicians did the speaker programs “very well.” But some didn’t. They put on what Babich would call “illegal sales programs,” where the physicians in- vited to the speaker dinners didn’t even show up. The Insys sales representative “may have signed forged sign-in sheets or done an- ything to make it look . . . to the corporate office that the program was done correctly in order to get the payment to the physician.” Babich admitted the speaker programs were illegal because “we traded cash for prescriptions.” Burlakoff joined Insys in June 2012. He came from an Insys competitor, Cephalon, where he had been in charge of speaker de- velopment in his role as Market Development Manager. He knew USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 12 of 32 12 Opinion of the Court 22-14192 Tondre, a Cephalon sales representative, and Chun, a pain medi- cine specialist. In June 2012, Insys did not have a speaker program. Soon after arriving at Insys, Burlakoff met Chun and learned that he had been trained as a speaker. Sometime later, in the summer of 2012, he went to dinner with Chun; Aqsa Nawaz, Chun’s girlfriend; and Tracy Kane, an Insys sales representative. They “talked about sev- eral things to try to break the ice, but ultimately the conversation revolved around [Burlakoff’s] desire to utilize [Chun] as a speaker in exchange for his business.” In Burlakoff’s words, “I needed him to write Subsys and a lot of it.” I said, listen, this is my position as Vice President of Sales, I have bosses to answer to, I do have a large budget, at least in respect -- in perspective to other pharmaceutical companies, I had 100,000, I let him know I had 100,000, I planned on using every Penni [sic] of it so long as he was prescribing Subsys in return. Chun “verbally agreed” with Burlakoff’s plan. Insys had a form speaker agreement drafted by legal counsel. On July 17, 2012, Chun became the first physician to sign the agree- ment. Babich signed for Insys. The agreement provided that the payment to the physician as speaker would be consistent with the fair market value of the services provided by the speaker and not based on the volume or value of any business the speaker gener- ated for Insys. As Burlakoff put it, the notion that the physician USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 13 of 32 22-14192 Opinion of the Court 13 would not be paid on the basis of the volume or value of any busi- ness he generated was “false.” It was “just fluff language that no one at the company reads, nor do any of the physicians read.” “If we didn’t have a 2-to-1 return on investment, that speaker no longer spoke.” Exhibit B to the agreement provided for a $2,400 honorarium for each program Chun conducted and $1,200 for any additional programs conducted the same day. Once the speaker program was fully underway, Insys’ Direc- tor of Sales targeted physicians he referred to as “high decile cus- tomers.” As Burlakoff explained, “the doctors [we]re decile based on . . . the number of prescriptions, net revenue and gross revenue they produce[d] for the rapid onset opioid market, so that would include us and all competitors, and then separately just Subsys.” Chun was a high decile customer. Insys’ Director of Sales Opera- tions “analyzed him as someone that was just an extremely high prescriber of the rapid onset opioid market.” Insys rated him as “a 10 for the rapid onset opioid market and an 8 or 9 for Subsys.” Bur- lakoff received an email from Babich stating: “Chun is the Six Mil- lion Man. A rep could theoretically make 600,000 a year just off him.” Burlakoff referred to doctors who would prescribe Subsys in return for speaker events as: “Game changers, President’s Club makers, a rep’s dream, you know, golden goose, I mean, but more often than not we used the term whales.” President’s Club makers, Burlakoff said, “meant that that physician, if he does what he says he’s going to do and prescribes Subsys in exchange for the speaker USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 14 of 32 14 Opinion of the Court 22-14192 programs we give him, he’s going to send the representative to President’s Club, which is the highest reward a representative can be given in the industry.” Burlakoff left Insys in the summer of 2015. Chun served as an Insys speaker from July 2012, when he signed the speaker agree- ment, until Burlakoff departed. Tondre, who made the arrange- ments for the majority of Chun’s speaker programs, testified that he set up 100 programs. By the time the Insys speaker program had run its course in 2015, Chun had received honoraria totaling $278,900. Michael Frey—a former family medicine physician who, in 2018, pleaded guilty twice to conspiracy to violate the Anti-Kick- back Statute, and, cooperating with the Government, 9 testified against colleagues in similar cases—was well acquainted with Chun. Frey attended a three-day “speaker training” session with Chun and over 50 other physicians in Boca Raton, Florida, on No- vember 14–16, 2014. He testified that during the session, he, Chun, Dr. De la Garza, and another physician were sitting at a table talk- ing about the speaker fees they were receiving, and that “Dr. Chun . . . bragged that he was the highest paid speaker in the country for his prescription writing.” The Government’s proof that the Count One conspiracy ex- isted as alleged was overwhelming. The jury found, and we affirm, 9 United States v. Michael Frey, M.D., No. 2: 18-cr-71-FLM-99CM, 2018 WL 2835942 (M.D. Fla. May 18, 2018). USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 15 of 32 22-14192 Opinion of the Court 15 that Chun conspired with four of his co-conspirators—Insys, Ba- bich, Burlakoff and Tondre—to violate the Anti-Kickback Statute. B. Substantive Counts We now move to Counts Two though Eleven, alleging the Anti-Kickback Statute crimes Chun, Tondre, and their Count One co-conspirators agreed to commit. The Anti-Kickback Statute states: Whoever knowingly and willfully solicits or receives any remuneration (including any kickback, bribe, or rebate) directly or indirectly, overtly or covertly, in cash or in kind-- (A) in return for referring an individual to a person for the furnishing or arranging for the furnishing of any item or service for which payment may be made in whole or in part un- der a Federal health care program, or (B) in return for purchasing, leasing, ordering, or arranging for or recommending purchasing, leasing, or ordering any good, facility, service, or item for which payment may be made in whole or in part under a Federal health care program, shall be guilty of a felony and upon conviction thereof, shall be fined not more than $100,000 or im- prisoned for not more than 10 years, or both. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 16 of 32 16 Opinion of the Court 22-14192 42 U.S.C. § 1320a-7b(b)(1) (emphasis added). 10 Chun is alleged to have committed the offenses described in Counts Seven through Eleven in 2015. 11 On May 4, 5, 11, 12 and June 22, respectively, he allegedly received kickbacks in the form of speaker honoraria for programs that took place in restaurants in Florida: in Sarasota on April 14 and 28, May 4 and 9, and June 16, and in Naples twice on May 8. The honoraria totaled $16,700. Chun presents two arguments in challenging these five counts. One is that the Government failed to tether the Insys speaker program scheme to the Anti-Kickback Statute federal healthcare requirement. The other is that the Government failed to prove that, in accepting the speaker fees, he acted with the spe- cific intent to disobey the law. We consider these arguments in turn. 1. Federal Healthcare Requirement The Anti-Kickback Statute prohibits a practitioner from “knowingly” accepting remuneration in exchange for “any item or service for which payment may be made in whole or in part under a Federal health care program.” 42 U.S.C. § 1320a-7b(b)(1). We have not addressed in a published opinion what the Government 10 The Government charged Tondre under Section 1320a-7b(b)(1)’s counter- part, 42 U.S.C. § 1320a-7b(b)(2), which makes “knowingly and willfully of- fer[ing] or pay[ing] any remuneration” a felony as well. 11 The offenses Tondre committed as alleged in Counts Two through Six oc- curred in 2015 on the same dates. On those dates, he paid Chun kickbacks in the amounts indicated in the text. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 17 of 32 22-14192 Opinion of the Court 17 must show to establish this element. But the Fifth Circuit addressed it in United States v. Shah, 95 F.4th 328 (5th Cir. 2024). There, the Court held that the Government need only show that the defend- ant “knowingly agreed to accept remuneration for referring pa- tients that could be federally insured.” Id. at 352. We choose to adopt the Fifth Circuit’s reading for two rea- sons. First, the statute requires only that the “payment may be made . . . under a Federal health care program.” 42 U.S.C. § 1320a- 7b(b)(1) (emphasis added). The word “may” suggests that the de- fendant is liable if there is a possibility that payment could come from a federal health care program. This makes sense given the na- ture of most medical practices, where Medicare constitutes a por- tion, but not the entirety, of the patients’ insurance coverage. Sec- ond, this reading is in line with the plain reading of 42 U.S.C. § 1320a-7b(h) (“[A] person need not have actual knowledge of this section or specific intent to commit a violation of this section.”). Here, the Government introduced evidence that Chun had participated in the Medicare program, and, therefore, that he had Medicare patients. Based on this, a jury had sufficient evidence to find that Chun knowingly agreed to accept remuneration for refer- ring patients who could be federally insured. 2. Specific Intent Willful conduct under the Anti-Kickback Statute requires that the act be “committed voluntarily and purposely, with the spe- cific intent to do something the law forbids.” United States v. Nerey, 877 F.3d 956, 969 (11th Cir. 2017) (quoting United States v. Vernon, USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 18 of 32 18 Opinion of the Court 22-14192 723 F.3d 1234, 1256 (11th Cir. 2013)). 12 Chun points to several pieces of evidence as proof that he lacked the specific intent to vio- late the law. First, he states that he was not aware ahead of time who or how many people would be attending the events. Second, he had no role in forging or submitting the forged sign-in sheets. Finally, Chun argues that from the circumstantial evidence in the record, the jury could not have found that he served as a speaker for Insys in exchange for writing Subsys prescriptions. While these points could have been persuasive at trial, the jury ultimately chose not to accept them. The evidence that Chun had the specific intent to do something the law forbids was over- whelming. He knew the speaker programs were shams, and he nevertheless collected payment for them. For example, several at- tendees testified that Chun’s programs lacked any educational component, were poorly attended, or were attended by inappro- priate people—such as family members. The jury also heard testi- mony that Tondre asked Chun who he wanted to invite to his speaker programs. The Government introduced evidence that dur- ing the time these sham events were occurring, Chun began pre- scribing more and more Subsys—proof that the speaker programs existed to induce him to prescribe more. 12 Chun also argues that the jury’s conviction for illegal renumerations re- quired an impermissible stacking of inferences. The stacking-of-inference ar- gument is a ubiquitous argument, made in countless criminal, and civil, cases. It is frivolous. So, we do not address it. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 19 of 32 22-14192 Opinion of the Court 19 As for the sign-in sheets, the Government introduced evi- dence that they contained forged signatures for each of the speaker events described in Counts Two through Eleven. Additionally, sev- eral attendees appeared on multiple sign-in sheets. And Chun’s nurse practitioner testified that her signature had been forged on multiple sign-in sheets and, in one instance, had been misspelled in the same way Chun frequently misspelled it. Not only does this contradict Chun’s argument that he had no role in forging the sign- in sheets, but it is also circumstantial evidence that he was aware of the illegitimate purpose of the speaker programs. Chun seems to have missed the essence of what made his conduct illegal. His crime was not forging the signatures of physi- cians and others who did not attend his programs. His crime was being paid to prescribe—for which the Government provided am- ple evidence. In sum, the jury had sufficient evidence to support its verdicts. 13 13 Tondre alludes to an insufficiency of the evidence argument for the substan- tive counts in the “Summary of the Argument” section of his initial brief. He argues that he did not pay Chun for the events nor did he cause Chun’s pay to be increased in any material way. Like with Chun, there was overwhelming evidence for the jury to find that Tondre acted with specific intent to do some- thing the law forbids. In addition to introducing evidence that Tondre forged the sign-in sheets, which he concedes, the Government also introduced evi- dence that Tondre was aware that the speaker programs were poorly at- tended, had inappropriate attendees, and lacked a proper educational compo- nent. A reasonable jury could easily find that Tondre knew the true purpose of the speaker programs was not to educate local physicians about Subsys, but rather to transfer cash from Insys to Chun in exchange for prescribing Subsys. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 20 of 32 20 Opinion of the Court 22-14192 C. Safe-Harbor Provision Finally, we address Tondre’s remaining challenge to the Dis- trict Court’s denial of his motion for judgment of acquittal. Tondre argues that there was insufficient evidence introduced at trial for the jury to convict him of participating in a conspiracy to violate the Anti-Kickback Statute. Specifically, he argues the Anti-Kickback Statute contains a safe-harbor provision for employees, and, as an employee of Insys, he is shielded from prosecution. Tondre did not raise this issue below. However, he asserts that since the safe har- bor provision is not an affirmative defense, but rather a broad ex- clusion of who the Anti-Kickback Statute applies to, his failure to raise the issue at the District Court does not constitute a waiver. The safe harbor provision of the Anti-Kickback Statute pro- vides that “Paragraphs (1) and (2) shall not apply to . . . any amount paid by an employer to an employee (who has a bona fide employ- ment relationship with such employer) for employment in the pro- vision of covered items or services.” 42 U.S.C. § 1320a-7b(3)(B). We have previously held that the safe harbor provision con- tained in 42 U.S.C. § 1320a-7b(3)(B) is an affirmative defense. See Vernon, 723 F.3d at 1271. Affirmative defenses, if not raised at trial, are waived. See United States v. Najjar, 283 F.3d 1306, 1308 (11th Cir. 2002). Because Tondre failed to raise this affirmative defense at trial, it is waived and we do not consider it further. USCA11 Case: 22-14192 Document: 108-1 Date Filed: 08/18/2026 Page: 21 of 32 22-14192 Opinion of the Court 21 II. JURY QUESTIONS Chun14 argues that, by answering two questions posed by the jury, the District Court invaded the province of the jury. “A trial judge has some obligation to make reasonable ef- forts to answer a question from the jury.” United States v. Rodriguez, 765 F.2d 1546, 1553 (11th Cir. 1985). The district court has consid- erable discretion when responding to jury questions, but it does not have the discretion to “misstate the law or confuse the jury.” United States v. Lopez, 590 F.3d 1238, 1247–48 (11th Cir. 2009). Challenged supplemental jury instructions are reviewed in light of the entire jury charge to determine whether the jury was misled. Id. at 1248. District courts should “answer within the specific limits of the ques- tion presented and resolve the jury’s difficulties with concrete ac- curacy.” United States v. Joyner, 882 F.3d 1369, 1375 (11th Cir. 2018) (internal quotation marks omitted). “We review a district court’s response to a jury question for an abuse of discretion.” Lopez, 590 F.3d at 1247. When applying an abuse of discretion standard,