How have the courts reviewed the first report of a plaintiff's medical malpractice case?

Commodore also contends that the district court's review of the magistrate's first report was defective because it was required to but did not hear all of the evidence itself before acting on the case. This argument is based on United States v. Bergera, 512 F.2d 391 (9th Cir.1975), in which the court held that protection of the integrity of the fact finding process requires that, before the district court may enter a judgment that disregards the recommendation of a magistrate who has heard all of the evidence, the district court must itself rehear all of that evidence. Id. at 393-94.