Is there any case law supporting the probability of negligence in medical malpractice cases?

The decisional law of California recognizes that the probability of a negligent cause in medical malpractice actions may be supplied by: (1) expert testimony; (2) common experience; or (3) circumstantial evidence in particular cases. The record of the case at bench discloses no expert testimony that the injury to appellant is one that ordinarily would not occur without negligence. While there is testimony that the injury was unexpected and unusual in isolation perfusion when due care is exercised, that testimony is in itself insufficient without further testimony that the unexpected or unusual result was probably the consequence of negligence. (Siverson v. Weber, 57 Cal.2d 834, 839, 22 Cal.Rptr. 337, 372 P.2d 97.) That further testimony is lacking here.