The Second Circuit today held, in a shareholder class action accusing Pfizer of concealing the cardiovascular risks of two drugs, that Judge Swain should not have excluded entirely the testimony of the plaintiffs’ damages expert — a decision which had effectively ended the case (see our prior posts here and here). The Second Circuit agreed with Judge Swain about the problems in the expert’s testimony, but ruled that she should have preserved the admissible portions:

When faced with expert testimony that contains both reliable and unreliable opinions, district courts often exclude only the unreliable testimony. This process of parsing expert testimony is consistent with Rule 702’s “liberal admissibility standards,” which favor allowing the jury to hear testimony that “both rests on a reliable foundation and is relevant to the task at hand.” Of course, district courts are “not obligated to prune away all of the problematic” elements of an expert’s proposed testimony “to save the remaining portions, however small.” But when the unreliable portion of an opinion can easily be distinguished from testimony that could help the jury, it may be an abuse of discretion to throw the good out with the bad.

The Second Circuit found that the expert’s errors in the Pfizer case were “but one small part of an extensive economic analysis.”

Our prior posts on the case are here.