Most courts require that litigants produce even privileged materials that the litigants have shared with their testifying experts—the waiver occurs when the testifying expert “considers” the materials, even if the testifying expert does not “rely” on the materials.
Courts have acknowledged that litigants hoping to shield privileged materials from discovery can try to prove that their testifying experts never read the materials. One court found that a testifying expert’s lack of memory about reviewing the documents did not carry this burden of proof, especially when the testifying expert acknowledged that “it is his firm’s regular practice to review documents” similar to those provided by counsel. Aniero Concrete Co. v. New York City Sch. Constr. Auth., No. 94 Civ. 9111 (CSH)(FM), 2002 U.S. Dist. LEXIS 2892, at *11 (S.D.N.Y. Feb. 22, 2002).
Litigants hoping to protect privileged materials from discovery should not share them with testifying experts, but should keep in mind the additional argument that the testifying expert never read the materials.