From a doctrinal standpoint, courts rely on a well-established principle: experts are permitted to testify to assist the fact-finder, not to persuade them with rhetorical flourish. Federal Rule of Evidence 702 permits experts to offer opinions grounded in their expertise, but that doesn’t open the floodgates to courtroom TED Talks. The moment an expert starts editorializing—injecting value-laden commentary, offering thinly veiled advocacy, or styling their testimony like an op-ed—they’ve crossed the line from helpful interpretation to persuasive advocacy. That’s what plaintiff’s expert, Dr. Fugh-Berman, a frequent flier in pharmaceutical litigation, tried to do in in United States es rel. Siegel v. Novo Nordisk, Inc., 2025 U.S. Dist. LEXIS 135854 (W.D. Wash. Jul. 16, 2025). But the court nudged her, not all that gently, back into her lane — behind the witness stand, not on the bench, at counsel table, or in the jury box.
Dr. Fugh-Berman was proffered to opine that defendant’s marketing and promotion of its drug used in the treatment of hemophilia caused physicians to use more of the drug and to use it for off-label purposes. Experts are supposed to play a role in helping the jury understand facts beyond common knowledge. So, calling an expert to testify that marketing is designed to increase sales seems a little like calling a marine biologist to confirm that fish live in water. No one in the jury box needs that explained. But we’ll allow, because the court did, that perhaps Dr. Fugh-Berman’s 35 years of researching pharmaceutical marketing will offer the jury something beyond common sense. However, there’s a line, especially with a marginally relevant expert — experts may illuminate, they should not pontificate.
That is why the court allowed testimony about what can influence a physician’s prescribing behavior generally, but precluded testimony that defendant’s “promotional methods” caused the plaintiff’s physician to prescribe the drug to plaintiff. Not only had the expert not reviewed any data specific to plaintiff or the prescribing physician, the ultimate causation question is a legal conclusion for the jury. Id. at *5-6.
While not all of the plaintiff’s expert’s opinions are spelled out in the decision, the court repeatedly made clear that she could “summarize” the promotional benefits offered to plaintiff and his physician and offer her opinion that they are the type of benefits that may influence physician prescribing behavior, but she could not offer opinions that crossed the line into argument or legal conclusions – such as these gifts/services influenced the prescriptions written or such promotion increased off-label use. Id. at *6. Those are legal conclusions cloaked in a lab coat.
Nor could plaintiff’s expert offer her “speculative editorial” factual narrative regarding defendant’s marketing practices:
[N]o expert shall testify in a form of an advocate editorializing, or present a conclusory narrative akin to attorney argument, rather than as an expert witness.”
Id. Otherwise, the courtroom division of labor gets a little blurry. Lawyers argue. Judges instruct. Juries decide. Experts inform. Once experts start slipping into the role of advocates, not only can juries become confused about who is doing what, legal conclusions dressed up as “professional opinions,” step on the toes of both the judge and the jury.
The court also excluded the expert’s opinions based on “discourse analysis” because it was not mentioned at all in her report. Id. at *4-5. And found she was not qualified to opine on whether a high dosage use of the product was “unproven.” Id. at *6.
We still take issue with whether her “expert” testimony will assist the jury in understanding evidence that is beyond their lay knowledge, but at least the court is making her pull up short of editorializing or offering legal conclusions. Afterall, editorializing is about helping the jury understand “why” certain evidence matters, and that’s our job. Let the lawyers argue, let the experts inform, and let the jury decide—without the running commentary.