The expert’s opinion must “fit” the case, and his ipse dixit that it does is never enough. General Elec. Co. v. Joiner, 522 U.S. 136, 146 (1997). Stephen Hawking would be a stunning witness in a case involving theoretical physics, but would never see the light of day in an accounting malpractice case.
Davis v. Duran 2011 WL 2277645, 5 (N.D.Ill.) (N.D.Ill.,2011)