What is the test for an error in a jury instruction in a medical malpractice case?

"In this situation, where a reviewing court concludes beyond a reasonable doubt that the omitted element was uncontested and supported by overwhelming evidence, such that the jury verdict would have been the same absent the error, the erroneous instruction is properly found to be harmless. We think it beyond cavil here that the error `did not contribute to the verdict obtained.' [Citation.]" (Neder v. United States, supra, 527 U.S. at p. 17, citing Chapman v. California, supra, 386 U.S. at p. 24.)