--- title: "FDA Expert Not Allowed to Opine on Regulatory Requirements" meta: "og:description": "The expertise of the FDA expert played no role in her opinion that a product with Zembrin is adulterated under federal law" "og:title": "FDA Expert Not Allowed to Opine on Regulatory Requirements" author: "Shuva Guha Thakurta" description: "The expertise of the FDA expert played no role in her opinion that a product with Zembrin is adulterated under federal law" --- # FDA Expert Not Allowed to Opine on Regulatory Requirements Posted on August 20, 2026 by Shuva Guha Thakurta Plaintiff Joann LeDoux, a nurse for the Army, alleged that Defendants' nootropic supplement kits were adulterated with amphetamines and other ingredients that Defendants failed to disclose. Defendants asked the Court to exclude expert evidence from Ms. [Evelyn Cadman](https://expertwitnessprofiler.com/expert-witness/Evelyn-Cadman/1573793), retained by Plaintiff to render "opinions regarding the regulatory status of the dietary supplement product" sold to Plaintiff by Defendants. According to Defendants, Cadman impermissibly "offers only legal advocacy—applying federal statutes and regulations to alleged facts and pronouncing whether Defendants violated the law—telling the Court and jury what judgments to reach." Defendants also asked the Court to strike Dr. [Gabriel Holguin](https://expertwitnessprofiler.com/expert-witness/Gabriel-Holguin/1578663)'s opinion about the "psychological impacts of the dietary supplement product sold to [Plaintiff]." Defendants argued that Holguin's opinion (1) is irrelevant because it concerns only claims which the Court has already dismissed and (2) is unreliable because it contains citations "hallucinated" by artificial intelligence. ![FDA Expert Not Allowed to Opine on Regulatory Requirements](https://cdn.jurimatic.com/images/blog_pic_640X480_2026_08_20T131839_364.webp) ## FDA Expert Witness [Evelyn D. Cadman](https://expertwitnessprofiler.com/expert-witness/Evelyn-Cadman/1573793) is a scientific and regulatory consultant with more than 25 years of experience in FDA-regulated industries. Cadman is the founder of FDA Compliance Simplified, a service of Cadman Consulting Services, LLC, and has advised clients worldwide on U.S. regulatory matters related to dietary supplements, foods, cosmetics, and over-thecounter drugs. [Want to know more about the challenges Evelyn Cadman has faced? Get the full details with our Challenge Study report](https://expertwitnessprofiler.com/order/add?eId=1573793&pId=3). ## Psychology Expert Witness Dr. [Gabriel Holguin](https://expertwitnessprofiler.com/expert-witness/Gabriel-Holguin/1578663) is a licensed clinical psychologist, and also a forensic psychologist. Holguin has extensive experience in the evaluation and treatment of active duty service members and veterans with complex mental health concerns, including substance use disorders, depression, anxiety, and trauma-related conditions. Over the course of his career, he has published peer-reviewed research in the field of clinical psychology and have worked in both military and civilian healthcare systems. [Gain a comprehensive understanding of Gabriel Holguin's qualifications and casework history with his Expert Witness Profile report](https://expertwitnessprofiler.com/order/add?eId=1578663&pId=3). ## **Discussion by the Court** ### _A. The Court grants Defendants' motion to exclude the testimony of Evelyn Cadman_ Cadman's analysis and conclusions relate solely to whether Defendants' products were "adulterated" under federal law or whether Defendants violated federal law in labeling or marketing those products. According to the Court, Cadman's opinion offers impermissible legal conclusions that are irrelevant because they do not "aid the jury in making its decision." Cadman's findings that Defendants violated federal regulations are similarly impermissible legal conclusions. Plaintiff argued that Cadman may opine on "general FDA regulatory requirements and procedures" and Defendants' compliance with them. But Cadman's opinion is distinguishable from those of other regulatory experts that courts have deemed admissible. Critically, Cadman does not offer any specialized knowledge about FDA requirements that would assist a jury. Instead, Cadman simply (1) identifies relevant statutes and regulations and (2) explains her conclusion that Defendants' conduct violated those statutes and regulations. For example, Cadman noted that Thesis' products contained Zembrin and that the FDA previously declined another company's use of Zembrin in a dietary supplement because of "insufficient verification of safety for human consumption." She then concluded that "accordingly, Zembrin's inclusion in a dietary supplement—absent an accepted NDI notification or exemption—renders the product adulterated under [21 U.S.C. § 342(f)(1)(B)](https://www.law.cornell.edu/uscode/text/21/342)." This reads much like a legal memorandum, making legal conclusions, commenting on the applicable law, and applying the law to the facts. Aside from her reference to a previous FDA decision—which she does not name or specify any details about—Cadman's expertise plays no role in her opinion that a product with Zembrin is "adulterated" under federal law. Absent the use of any specialized knowledge, it is improper for Cadman to advance these arguments "cloaked with the mantle of an expert" and perhaps "carry special weight with the jury." The Court granted Defendants' motion to exclude Cadman. ### _B. The Court grants Defendants' motion to exclude the testimony of Dr. Gabriel Holguin_ First, Plaintiff has agreed to withdraw the first three of four opinions in Holguin's expert report "because they were linked to consequences of the positive drug test results" and the theory of liability the Court found was unavailable to Plaintiff when it granted partial summary judgment. Holguin's fourth and only remaining opinion is as follows: "**4. Time-linked symptom course consistent with stimulant withdrawal and stress response** **The marked fatigue, hypersomnia, cognitive fog, and mood lability reported in October 2021 after abrupt cessation of Thesis products are consistent with the clinical course of stimulant/amphetamine withdrawal and stress-related decompensation—especially when superimposed on occupational and psycholegal stressors. Plaintiff described under oath about the intense fatigue and concentration problems she experienced after stopping the supplements; subsequent negative urine/hair testing after cessation dovetails with the reported symptom course. The acute symptom pattern is consistent with clinical reviews of amphetamine withdrawal. Additionally, when depressive and anxiety symptoms arising from her court-martial, flagging, and removal from clinical duties are considered alongside the physiological symptoms of stimulant withdrawal, the combined burden and multifaceted and complex clinical picture can result in a synergistic impact. In clinical terms, the psychiatric stressors and the neurochemical withdrawal would be expected to exacerbate one another, thereby intensifying both the severity and duration of functional impairment.**" According to Defendants, Holguin's opinion that Plaintiff experienced symptoms "consistent with the clinical course of stimulant/amphetamine withdrawal" is "rendered. . . irrelevant" by the Court's "disposing of Plaintiff's amphetamines theory." The Court's partial summary judgment order does not preclude Holguin's fourth opinion. That order dismissed claims "to the extent they (1) relied on allegations of amphetamine adulteration and (2) claimed damages caused by Plaintiff's positive test for amphetamines." Defendants' broad reading would preclude any claims based on amphetamine adulteration at all, which is not what this Court intended. Rather, the Court barred claims based on Plaintiff's "urinalysis theory" that amphetamine adulteration caused Plaintiff to test positive on a drug screening. The claim that Plaintiff ingested adulterated products (whether with amphetamines, other stimulants, or other ingredients) that caused negative health effects was not precluded by the Court's ruling, nor were any otherwise-admissible expert opinions which relate to that claim. But Holguin's report also contains "hallucinated" citations to academic articles which appear generated by artificial intelligence. Because Plaintiff withdrew the portions of Holguin's opinion containing these citations, the Court did not address them when it ordered Plaintiff's counsel to show cause—and ultimately sanctioned her—for her unverified use of generative artificial intelligence and submission of false citations to the Court. Defendants argued that, even though these citations exist only in the withdrawn portions of Holguin's opinion, they "irreparably undermine Holguin's credibility, rendering his opinions unreliable." The Court agreed with Defendants and found that Holguin's multiple hallucinated citations "shatter his credibility with this Court." While Plaintiff's counsel was not asked to provide information about these citations, the errors are similar to those in other expert reports where she "used Claude or ChatGPT to 'generate a formatted citation table' for academic articles and 'provided the same AI-generated citation table to both experts as an appendix, and neither expert caught the errors in the citation data before signing their reports.'" This level of involvement from counsel in drafting (with AI) the list of materials supposedly relied upon by Holguin, and Holguin's lack of diligence in verifying the sources that he represented were the basis for his opinion, prevent Plaintiff from meeting her burden to show that Holguin's opinion is "based on sufficient facts or data," is "the product of reliable principles and methods," or "reflects a reliable application of the principles and methods to the facts of the case." Thus, although these errors occur only in the withdrawn portions of Holguin's opinion, they "undermine the overall credibility" of the report. The Court found that the hallucinated citations undermine Holguin's entire report and that the report is not reliable. ## **Held** The Court granted Defendants' [_Daubert_](https://www.law.cornell.edu/wex/daubert_standard)__motions to exclude the testimony of Evelyn Cadman and Dr. Gabriel Holguin. ## **Key Takeaway** If an expert witness uses terms that have a specialized meaning in the law and that "represent an attempt to instruct the jury on the law, or how to apply the law to the facts of the case," the testimony is an impermissible legal conclusion. Terms such as "new dietary ingredient" and "adulterated" have a "separate, distinct and specialized meaning in the law different from that present in the vernacular." ## **Case Details:** | Case Caption: | Joann Ledoux V. Outliers Inc. | | --- | --- | | Docket Number: | 3:24cv5808 | | Court Name: | United States District Court, Washington Western | | Order Date: | August 18, 2026 | --- ## **You Might Also Like** ![FDA Expert Not Allowed to Opine on Regulatory Requirements](https://cdn.jurimatic.com/images/blog_pic_640X480_2026_08_20T131839_364.webp) [**FDA Expert Not Allowed to Opine on Regulatory Requirements**](https://expertwitnessprofiler.com/fda-expert-not-allowed-to-opine-on-regulatory-requirements/fda-expert-not-allowed-to-opine-on-regulatory-requirements)![Civil Engineering Expert Not Allowed to Opine on Nose Moldings](https://cdn.jurimatic.com/images/blog_pic_640X480_2026_08_19T194149_406.webp) [**Civil Engineering Expert Not Allowed to Opine on Nose Moldings**](https://expertwitnessprofiler.com/fda-expert-not-allowed-to-opine-on-regulatory-requirements/civil-engineering-expert-not-allowed-to-opine-on-nose-moldings)![Law Enforcement Experts Not Allowed to Opine on Sound Professional Standards](https://cdn.jurimatic.com/images/blog_pic_640X480_2026_08_19T171339_258.webp) [**Law Enforcement Experts Not Allowed to Opine on Sound Professional Standards**](https://expertwitnessprofiler.com/fda-expert-not-allowed-to-opine-on-regulatory-requirements/law-enforcement-experts-not-allowed-to-opine-on-sound-professional-standards)![Towing Expert Was Allowed to Opine on Practices Relevant to Invoicing](https://cdn.jurimatic.com/images/blog_pic_640X480_2026_08_18T200404_852.webp) [**Towing Expert Was Allowed to Opine on Practices Relevant to Invoicing**](https://expertwitnessprofiler.com/fda-expert-not-allowed-to-opine-on-regulatory-requirements/towing-expert-was-allowed-to-opine-on-practices-relevant-to-invoicing)![Market Research Expert Allowed to Opine on Consumer Perception](https://cdn.jurimatic.com/images/blog_pic_640X48000.webp) [**Market Research Expert Allowed to Opine on Consumer Perception**](https://expertwitnessprofiler.com/fda-expert-not-allowed-to-opine-on-regulatory-requirements/market-research-expert-allowed-to-opine-on-consumer-perception)