Benkendorf v. Advanced Cardiac Specialists, __Az. Adv. Rep. __, 1 CA-CV 09-0697 (App. Div. I, January 24, 2012) (J. Brown)
WHILE PLAINTIFF MUST PROVE CAUSATION IS PROBABLE, DEFENSE MAY CHALLENGE CAUSATION WITH EXPERT TESTIMONY AS TO WHAT IS POSSIBLE
Plaintiff's wife underwent surgery to remove a cancerous kidney. Thereafter she developed a blood clot and died. Plaintiff brought a medical malpractice wrongful death case alleging Advanced Cardiac Specialists was negligent in the administration and monitoring of Coumadin and that this caused the brain hemorrhage which killed plaintiff's decedent. Plaintiff filed a motion in limine attempting to preclude the defense expert from testifying as to alternative “possible” causes of the decedent's death. Plaintiff argued that in medical negligence cases causation must be proven to a “reasonable degree of medical probability.” Although the defense expert did testify that the decedent's “outcome” would “probably” be the same with or without better monitoring of the Coumadin, he also testified that there were other “possible” causes of the decedent's death including her age, hypertension, the removed kidney tumor and her history of stroke. Plaintiff's motion in limine was denied, the jury returned a defense verdict and the Arizona Court of Appeals affirmed.
The court of appeals first acknowledged that a plaintiff, because he has the burden of proof, must indeed prove causation to a reasonable degree of medical probability. However, the same is not true for the defense because the defense has no burden and may choose “merely to rebut plaintiff's evidence.” In noting that this holding was consistent with the majority rule, the court seemed to at least imply that testimony as to “possible” causes may need to be accompanied by testimony that defendant's conduct was “probably” not the cause and that such testimony is particularly admissible when plaintiff's expert testifies that no other cause could have been the cause of the plaintiff's injury. Further the court noted that the trial judge has broad discretion to nonetheless preclude such testimony if it deems it speculative or otherwise unreliable and without adequate foundation.
[Editors Note: the new expert witness evidentiary rules (http://www.azleg.gov/FormatDocument.asp?inDoc=/ars/12/02203.htm&Title=12&DocType=ARS) (ARS sec. 12-2203) recently adopted by our supreme court were not applicable to this case. It will be interesting to see how they impact upon this holding in future cases. While the statute does increase the trial court's scrutiny of the reliability of expert testimony it does not distinguish between a plaintiffs' expert and a defendants' expert, nor does it reference the burden of proof.]