McDaniels

MEMORANDUM *

After appellant Don McDaniels was terminated from his job at a refinery operated by appellee Mobil Oil (“Mobil”) in 2000, he sued for wrongful termination and disability discrimination. Prior to trial, Mobil filed a motion in limine to exclude on collateral estoppel grounds any evidence and arguments related to “environmental issues” litigated in an earlier state court action resolved against McDaniels. The district court granted the motion without explanation, the jury subsequently entered a verdict for Mobil, and McDaniels now appeals. He argues that the district court’s pre-trial decision to exclude evidence was in error. We agree, and reverse as to the retaliation claim. We affirm on the discrimination claim, however, because the evidentiary error was harmless as to that claim.

A. Collateral Estoppel

California rules of issue preclusion apply in this diversity action. See Jacobs v. CBS Broadcasting, Inc., 291 F.3d 1173, 1177 (9th Cir.2002); Pardo v. Olson & Sons, Inc., 40 F.3d 1063, 1066 (9th Cir.1994) (“Because this is a diversity case, we apply the collateral estoppel rules of the forum state.”). In California, collateral estoppel precludes a party from…