Opinion ID: 1458041
Heading Depth: 4
Heading Rank: 1

Heading: Required Disclosure of Expert Testimony Used to Contradict

Text: Rule 26 does not require the disclosure of evidence used solely for impeachment purposes. See Fed.R.Civ.P. 37(c) advisory committee's note (1993). The district court did not err by concluding that Rule 26(a)(2) required disclosure of Dr. Halbridge's supplemental testimony, however, because it is not impeachment evidence of the kind exempted from disclosure. Impeachment is an attack on the credibility of a witness. Sterkel v. Fruehauf Corp., 975 F.2d 528, 532 (8th Cir. 1992). To attack the credibility of witnesses by the presentation of evidence showing that facts asserted or relied upon in their testimony are false is to impeach by contradiction. 27 Charles Alan Wright & Victor James Gold, Federal Practice and Procedure § 6096 (1990). It does not impeach, however, to show that an expert's opinion about the meaning of facts merely differs from that of other experts. See Kennemur v. California, 133 Cal.App.3d 907, 184 Cal.Rptr. 393, 402 (1982). It is often difficult to distinguish between foundational facts and expert opinion, and so to distinguish between impeachment and substantive evidence, see id. at 403, but Rule 26(a)(2)(C)(ii) resolves the dilemma in favor of disclosure by requiring parties to disclose expert testimony offered to contradict the expert testimony of the opposing party. Because Wegener offered Dr. Halbridge's supplemental testimony to contradict the testimony of Johnson's experts, she was required to disclose it.