What is the test for an expert opinion in a medical malpractice case?

"Testimony in the form of an opinion that is otherwise admissible is not objectionable because it embraces the ultimate issue to be decided by the trier of fact." (Evid. Code, 805; see People v. Cole (1956) 47 Cal.2d 99, 105 [courts "have refused to hold that expert opinion is inadmissible merely because it coincides with an ultimate issue of fact"].) Thus, the trial court erred in finding the testimony inadmissible because it related to an ultimate issue in the case.