Does section 3854 require a defendant to prove that his negligence was a proximate cause of the employer's workers' compensation benefits?

[29 Cal.3d 930] In Mendenhall v. Curtis (1980) 102 Cal.App.3d 786, 162 Cal.Rptr. 569, the trial court, as here, had ruled that section 3854 precluded a defendant from litigating the question of whether his negligence was a proximate cause of the compensation benefits paid by an employer. A jury had returned special verdicts finding that (1) as between the employee and defendant the defendant's conduct, while negligent, was not a proximate cause of the employee's injuries, and (2) as between the employer and defendant, the latter was 100 percent negligent. The court thereupon entered judgment for the employer in the full amount of the employee's workers' compensation[633 P.2d 992] benefits, reasoning that section 3854 required the employer's liability for such benefits "to be deemed the proximate result of the accident." (Id., at p. 789, 162 Cal.Rptr. 569.)