Last week's Privilege Point summarized a case confirming non-testifying experts' general immunity from discovery — absent "exceptional circumstances" such as destructive testing. Ten days later, another court addressed discovery of what are called "dual hat" experts — providing both consulting advice and testimony.

In Clark v. Quiros, prison officials sued by an inmate for allegedly depriving her of medically necessary treatment retained a doctor as a testifying expert, and also as a consulting expert "to advise defendants on their prospective management and treatment of plaintiff." Case No. 3:19-cv-575 (VLB), 2022 U.S. Dist. LEXIS 154800, at *2-3 (D. Conn. Aug. 29, 2022). The court first acknowledged that non-testifying consulting experts are "generally immune from discovery." Id. at *7 (citation omitted). The court then noted that "for dual-hat experts, the privileges that apply to consultant communications and work product only apply when there is no overlap between the expert's consulting and testifying roles." Id. at *25. Such experts thus may claim work product protection "only over those materials generated or considered uniquely in the expert’s role as consultant." Id. at *22-23 (citation omitted). After reviewing the "dual hat" expert's documents in camera, the court found the necessary separation — and protected the consultant-role documents.

It can be difficult enough to apply a non-testifying consulting expert's "exceptional circumstances" standard, let alone deal with the added complication of "dual hat" experts. Litigants considering such a risky "dual hat" expert should carefully document the entirely separate nature of the two roles.