In Pacific Freight Lines v. Ind. Acc. Com. (1945) 26 Cal.2d 234, the commission's award of death benefits was annulled by the California Supreme Court which held that the evidence showed without substantial conflict that the death was caused "soley" by intoxication. However, the court was not delineating the degree of causation required to establish the defense, but was relying on the lack of conflicting evidence as a basis to overturn the decision. Justice Carter dissented, stating: "In addition to proving intoxication the employer had the burden of proving that the intoxication was the sole cause of the accident. The evidence on that subject is of only two kinds, that is, expressions of opinion, which, as above shown, were not binding on the commission, or an inference that because Oates was intoxicated when the accident occurred, the accident was caused by that intoxication . . . . The commission was not obligated to draw that inference." ( Id., at pp. 242-243.)