What is the test for granting relief in a medical malpractice case?

5 In the Brazil v. Silva, case, supra, 181 Cal. at page 498, 185 P. 174 at page 178, incidentally, the following observation is peculiarly here pertinent: 'In this connection, since the cause must go back for trial, it may not be amiss to call attention to the rule that, because of the very nature of these cases, the fraud or other wrong relied on must be proven clearly and satisfactorily. The relief asked for is so extraordinary, and the opportunity for false testimony so great, since the evidence in most cases must be largely parol, that it is only where it is fairly certain that the circumstances calling for the relief actually exist that the extending of it may be justified.'