Tort ExpertIn 2015, the plaintiffs in product liability litigation against the manufacturer of Accutane were dealt a stunning blow when the presiding judge rejected much of their tort expert witness testimony on causation issues. See, e.g., Sindhu Sundar (1),[1]  “Accutane Ruling Blocking Expert Testimony Kills 2K Suits,” Law360, May 11, 2015. Concluding that the plaintiffs’ experts were “cherry picking evidence,” the court sided with defense tort expert witnesses instead. See id. The latter experts were able to provide persuasive evidence indicating that the plaintiffs’ witnesses had “disregarded nine epidemiological studies from the past five years that found no link between Accutane and Crohn’s disease,” which was the condition alleged to have been caused by the product at issue. Id. Various components of the Accutane case have highlighted the importance of tort expert witness involvement in mass lawsuits, particularly product liability and pharmacological cases.


Mass tort litigation involves similar claims of multiple (in this case thousands) of plaintiffs against one or more defendants. See, e.g., Ronald V. Miller, Jr., “What is a Mass Tort?” Lawsuit Information Center, Jul. 27, 2015. There are typically common questions of law of fact that arise from the same series of transactions or occurrences in a mass tort, and the various cases are consolidated by procedural rules governing joinder. See, e.g., Paul D. Anderson, “Understanding the Difference Between Mass Torts & Class Actions,” NFL Concussion Litigation, Mar. 29, 2012. In recent years, mass torts have often been largely concerned with litigation over the alleged harms caused by a particular drug or device.

The consolidated action against Accutane’s manufacturer provided a good example for attorneys, in that it demonstrated just how critical tort expert testimony is in pharmaceutical mass lawsuits. At one point, the presiding judge conducted several Daubert-style hearings of the myriad expert witnesses involved in the case. See, e.g., Sindhu Sundar (2), “Accutane Ruling Shows Experts’ Power to Shape Mass Torts,” Law360, Feb. 23, 2015.

Cases such as Accutane’s often involve thousands of claimants; over 6,700 lawsuits were filed in that instance. See id. Moreover, legal analysts nationwide carefully follow such high profile litigation in an effort to see what sorts of arguments might or might not work, what precedents (if any) will be set, and how the mechanics of such cases play out. In addition, attorneys should pay close attention to what role tort expert testimony plays, how various experts are treated by the court, and what types of experts are most important. The type of experts that play a role in a pharmaceutical mass tort are myriad, and include epidemiological and medical professionals, pharmacological engineers, and experts who can address specific causation theories in product liability cases.

The Accutane case offers several important lessons. First, it suggests that attorneys must be extremely well-prepared in selecting the right tort expert witnesses. As one legal analyst explains, “[T]he potential impact of [the court’s] decision…highlights the reason disputes over the admission of expert testimony in pharmaceutical mass torts have grown more aggressive in recent years: They have the power to shut down major parts of the case, if not all of it.” Id.  Accordingly, attorneys should make sure that their experts can pass rigorous Daubert-style challenges from highly combative opponents and judges who will carefully scrutinize tort expert evidence. Litigators should also understand that when one expert loses, another wins. For example, the defense was able to defeat a specific plaintiff experts’ theory on causation by providing its own experts, who were better prepared and pointed out the shortcomings of the former witnesses. See, e.g., Sindhu Sundar (1), supra. The best way to challenge an opposing expert is not simply to rely on clever cross examination; truly savvy attorneys will provide expert witnesses of their own who can provide scientific explanations as to why an opposing expert should be disbelieved or precluded from testifying.

Another lesson that can be gleaned from the Accutane litigation is that how expert evidence gets handled (and whether it gets admitted at all) is not merely an issue that concerns one side. Instead, “‘The intensity of the parties’ commitment to the fight may be higher these days, because if the plaintiff wins, the defendant understands that this type of evidence will be heard by a jury, and it influences how the defendant evaluates the case,… . If the plaintiff loses, then the case may be ripe for summary judgment.’” Id. (quoting Professor of law William Janssen). In short, no matter which party prevails in a Daubert-type challenge, that party has helped to potentially secure a favorable outcome in the litigation as a whole.

Yet another important takeaway from the Accutane litigation is that tort expert witnesses are indispensable with respect to causation issues in pharmaceutical mass lawsuits. See id. The reason for this is that in such cases, “a court and a jury must rely primarily on scientific proof to determine whether the product at issue truly caused an alleged injury.” Id. Unlike in other cases, such as an auto accident lawsuit, where a lay witness could say what happened, in pharmaceutical litigation, that kind of evidence doesn’t exist. See id. Drug liability lawsuits are frequently based on long passages of time, so only an expert witness, using the techniques and tools that are available to the scientific community, would be able to evaluate causation in such a case. When thousands of plaintiffs are involved in a given case, whether or not causation can be proven is critical and can result in immense gains or losses for a particular side. Accordingly, as the Accutane case has demonstrated, attorneys should retain the best experts they can on the issue of causation, and these experts should be vetted and prepared for Daubert-like challenges.


Mass torts can be complex and difficult to navigate. The Accutane litigation was particularly complicated. Different judges made opposing findings regarding certain expert testimony, and certain tort expert evidence was accepted initially but later rejected after subsequent objections. Regardless of which side a litigant is on, expert testimony is clearly critical in such cases. Attorneys should anticipate aggressive battles over such evidence and realize that the entire outcome of a case may be at stake if qualified experts are not retained and properly prepared.


By: Kat S. Hatziavramidis, Attorney-at-Law

[1]          There are two articles written by the same author. In order to differentiate between the two when referencing them, the first full citation will be referred to as Sundar (1), and the second will be Sundar (2).