The United States Court of Appeals for the Sixth Circuit has ruled that all material given to testifying expert witnesses must be disclosed, including attorney opinion work product materials.
The circuits have been split on this issue. In Regional Airport Authority of Louisville and Jefferson County v. LFG, LLC, Case No. 05-5754 (6th Cir. Aug. 17, 2006), the court clarified the law in the Sixth Circuit.
The precise holding: "The bright-line approach is the majority rule, represents the most natural reading of Rule 26, and finds strong support in the Advisory Committee Notes. Therefore, we now join the "overwhelming majority" of courts . . . in holding that Rule 26 creates a bright-line rule mandating disclosure of all documents, including attorney opinion work product, given to testifying experts." (Emphasis added.) Don’t try to argue that whatever information you gave to the expert wasn’t considered by the expert and therefore is not discoverable; the word "given" was deliberately chosen by the court to void that argument.
Read the opinion here. The discussion of the discovery issue begins on page 14.
Thanks to the Sixth Circuit Blog for directing me to the decision.