If we are to believe our favorite TV shows, the expert witness process is a rather impromptu affair. Counsel selects an expert witness (often with little to no assistance or research – heresy!) and that witness abruptly testifies, often with shocking results.
The truth is that both sides of a case almost always know what an expert witness will say on the stand. That’s because every expert is required to work with counsel to complete an expert report that is submitted to all involved parties long before the trial begins. This report, according to the Federal Rules of Civic Procedure, must be a “complete statement” of all the expert’s relevant opinions before trial.
The challenges inherent in this requirement are immediately obvious. First, it’s hard for anyone to provide a “complete statement” of all of their opinions on a topic in a single report. More importantly, trials are not fixed entities. New information, facts, issues, and strategies can and do come up throughout the course of a trial that have direct bearing on expert testimony. While some leeway exists around an expert’s ability to deviate from the opinions in his or her report – the Federal Rules do not “limit an expert’s testimony simply to reading his report” but assumes that the expert will “supplement, elaborate upon, explain and subject himself to cross-examination” – the expectation is that testimony will stick closely to the prearranged script. If the expert steps too far out of bounds, his or her testimony risks becoming inadmissible.
So when the circumstances of the trial inevitably evolve, what’s an expert to do? As mentioned in a recent Law360 article, “Whether the expert (i) may simply clarify or elaborate upon the opinions in the report through trial testimony or (ii) must issue a supplemental report explaining new opinions or new bases for the original opinions is not always clear.”
When do you need a supplemental report?
Most simply, it is necessary to submit a supplemental report if an expert witness plans to testify about new opinions or opinions that are different from those in the original report, or does so during his or her deposition. Federal Rule 26(e) states that a supplemental report is required “if [a] party learns that in some material respect the [expert report] is incomplete or incorrect, and if additional or corrective information has not otherwise been made known to the other parties during the discovery process or in writing.” These updates must be submitted to the court, under the same Rule, by the time the party’s pretrial disclosures are due.
The Law360 article states that “where an expert offers an opinion during a deposition that contradicts or departs from the expert report, a duty to supplement arises… On the other hand, where an expert testifies at a deposition or submits a declaration that merely provides ‘evidentiary details’ that ‘undergird’ the conclusions in the initial report… there is no duty to supplement.” This sounds like a clear distinction, but often becomes blurry. It is further complicated by factors such as prejudice by the individual parties and the circumstances of the expert reports. In one case, for instance, the defendants had an expert report for over a year without asking the plaintiffs to supplement it, but then attempted to have it precluded because it was based on only a preliminary review. The court declined.
Courts also don’t take kindly to excessive supplementation. Rule 26(e) admonishes that expert witnesses may not “continually bolster, strengthen, or improve their reports by endlessly researching the issues they already opined on or to continually supplement their opinions.” When supplemental reports are excluded, it is often because the court believe that their inclusion will damage the proceedings or draw them out indefinitely. Whether or not a supplemental report from an expert witness is allowed often depends less on the information itself, and more on the circumstances of its admission.
What’s the takeaway here? For both attorneys and expert witnesses, work hard to submit the most complete expert report possible at the outset of a trial. If the need to supplement your report arises, look to both the letter and the spirit of Federal Rule 26(e) as guidance – but pay attention to your individual scenario as well.