What is the test for an employer's exclusive remedy provisions in a medical malpractice case?

As we explained recently in Shoemaker v. Myers, supra, 52 Cal.3d 1, 16, 276 Cal.Rptr. 303, 801 P.2d 1054: "[T]he legal theory supporting such exclusive remedy provisions is a presumed 'compensation bargain,' pursuant to which the employer assumes liability for industrial personal injury or death without regard to fault in exchange for limitations on the amount of that liability. The employee is afforded relatively swift and certain payment of benefits to cure or relieve the effects of industrial injury without having to prove fault but, in exchange, gives up the wider range of damages potentially available in tort. [Citations]."