Many courts address the discovery available from a litigant's testifying experts. Fewer courts assess discovery of a litigant's consultant retained to provide background expertise rather than testifying.

In Haile v. Detmer Sons Inc., 194 N.E.3d 883 (Ohio Ct. App. 2022), a plaintiff sued the company which serviced his mother's gas furnace, after she died of carbon monoxide poisoning. The lower court ordered production of the plaintiff's non-testifying consultant's post-accident inspection of the gas furnace. The appellate court reversed, bluntly noting "[t]he general rule . . . that the work of a [party's] consulting, non-testifying expert is protected from discovery requests of the opposing party." Id. at 887. The court specifically pointed to Ohio's rule that parallels Fed. R. Civ. P. 26(b)(4)(B) – allowing discovery of a non-testifying consulting expert only upon a showing of "exceptional circumstances under which, it is impractical for the party to obtain facts or opinions on the same subject or other means" – as when the consulting expert conducts destructive testing, changes the site conditions, etc. Id. (citation omitted). The appellate court noted that the trial court had erred by allowing discovery "without conducting an evidentiary hearing or an in camera review of the consulting expert's file and work product." Id. at 888. Most importantly, the appellate court emphasized that the consultant's inspection was "non-destructive in nature" and instead involved only a "visual and photographic inspection." Id. at 886.

Fed. R. Civ. P. 26(b)(4)(B) and parallel state rules provide consulting experts nearly complete immunity from discovery. Many courts bar discovery of such consultants' identities or even of their existence. Next week's Privilege Point will address what are called "dual hat" experts.