Is there a distinction between what is “possible” and what is “probable”? This issue was discussed in the case of A. Teichart & Son, Inc. v. WCAB, 73 Cal. Comp. Cas 1621.

This case involved Raul Barron, an employee of Teichart. Mr. Barron was involved in an argument with his supervisor, Darrell Gardner. The argument was observed by Mr. Barron’s brother-in-law, Daniel Cuevas. After the argument, Barron approached Cuevas and stated: “I can’t believe this s%&t. I’m out of here!” Barron then walked towards his company truck. A few minutes later, Barron was found slumped over the steering wheel of his truck dead. He died from the rupture of a congenital aneurysm.

The contention was that the argument caused Barron’s anger, that the anger caused a spike in his blood pressure, and that the spike in blood pressure caused the aneurysm to burst. The only medical report submitted at the time of trial was applicant’s QME report of Dr. Sherman. The issue at trial was whether the reporting of Dr. Sherman was sufficient on the issue of industrial causation.

Dr. Sherman’s report stated that “it is medically possible [that Barron] may have become angered at his supervisor and that this anger may have been translated into increased blood pressure, with the increased blood pressure then leading to the rupture of a presumed aneurysm…however, there is no way one can say with reasonable medical probability that this chain of events actually occurred…all we can say is that this is one possible scenario.”

The WCJ found that because Barron’s anger was proven at the time of trial and that since anger can lead to a spike in blood pressure, this was sufficient to establish a causal connection between Barron’s death and his employment. The WCJ relied on the McCalister case in reaching his conclusion that medical certainty is not required to show a connection between injury and job. (McCalister v. WCAB, (1968) 69 Cal. 2d 408). A petition for reconsideration was filed and the WCAB adopted the WCJ’s decision and denied reconsideration.

On appeal, the Court overturned the lower Court. The Court concluded that there was no substantial evidence as to industrial causation. “The decisive factor is whether applicant produced evidence showing it was reasonably probable that Barron’s anger, which arose from his workplace argument with his supervisor, caused his aneurysm to rupture.”

The Court quoting McCalister stated that a “reasonable or probable casual connection will suffice; [but] it is to be distinguished from the merely possible.” The Court had problems with the fact that Dr. Sherman merely said that the death was “possibly” caused by the anger which may have triggered the aneurysm to burst. The Court stated that there is a clear distinction between what is possible and what is probable. The correct standard is reasonable medical probability. Dr. Sherman’s report did not meet this standard.