It’s not what happened, but why: First Circuit rejects conclusory, unsupported expert opinions

It is not uncommon for an opposing expert to opine that the existence of injury alone implies negligence, nor is it unusual to find that such opinions are supported only by general reliance on “literature” with no discernible connection to the issue at hand. Certainly, Federal Rule of Civil Procedure 26(a)(2)(B) requires an expert’s report to contain “a complete statement of all opinions the witness will express and the basis and reasons for them.” And, Federal Rule of Evidence 702 requires that an expert not only base an opinion on sufficient facts or data but also reliably apply his or her methodology to those facts or data. Yet all too often, courts decline to hold an expert to task and instead find that these deficiencies go to the weight, but not the admissibility, of an expert’s opinion. But, as recently observed by the First Circuit, an expert must do more than merely cite the existence of an injury if a res ipsa loquitur argument is not available. And regardless, an expert’s failure to link the literature cited to the opinions offered is not a matter of insufficiency, but rather of unreliability.