Is a co-worker immune from liability in a civil action?

There are, however, statutory exceptions to coemployee immunity. As relevant here, a civil suit is permissible when an employee proximately causes another employee's injury or death by a "willful and unprovoked physical act of aggression" ( 3601, subd. (a)(1)) or by intoxication. ( 3601, subd. (a)(2).)⁴ If an employee brings a lawsuit against a coemployee based on either of these exceptions, the employer is not "held liable, directly or indirectly, for damages awarded against, or for a liability incurred by the other employee . . . ." ( 3601, subd. (b).) This provision is consistent with the view that a coemployee is immune from suit to the extent necessary to prevent an end-run against the employer under the exclusivity rule. (Saala v. McFarland, supra, 63 Cal.2d at p. 130, 45 Cal.Rptr. 144, 403 P.2d 400.) "It is self-evident that Labor Code section 3601 did not establish or create a new right or cause of action in the employee but severely limited a preexisting right to freely sue a fellow employee for damages." (Miner v. Superior Court (1973) 30 Cal.App.3d 597, 600, 106 Cal.Rptr. 416.)