Pat had been under the care of a cardiologist for three years prior to submitting to an elective operation that was performed by Surgeon. Two days thereafter, Pat suffered a stroke, resulting in a coma, caused by a blood clot that lodged in her brain. When it appeared that she had entered a permanent vegetative state, with no hope of recovery, the artificial life-support system that had been provided was withdrawn, and she died a few hours later. The withdrawal of artificial life support had been requested by her family, and duly approved by a court. Surgeon was not involved in that decision, or in its execution. The administrator of Pat's estate thereafter filed a wrongful death action against Surgeon, claiming that Surgeon was negligent in having failed to consult a cardiologist prior to the operation. At the trial the plaintiff offered evidence that accepted medical practice would require examination of the patient by a cardiologist prior to the type of operation that Surgeon performed. In this action, the plaintiff should 
prevail, if Surgeon was negligent in failing to have Pat examined by a cardiologist prior to the operation.  prevail, if the blood clot that caused Pat's death was caused by the operation which Surgeon performed.  not prevail, absent evidence that a cardiologist, had one examined Pat before the operation, would probably have provided advice that would have changed the outcome.  not prevail, because Surgeon had nothing to do with the withdrawal of artificial life support, which was the cause of Pat's death.