Is an employer an indispensable party to an action?

Tate v. Superior Court (1963) 213 Cal.App.2d 238, 28 Cal.Rptr. 548, held the employer was not an indispensable party to the action despite the third party's assertion of a Witt defense. In the course of so holding, Tate compared the employee's position to that of "a trustee of an express trust or a person expressly authorized by statute [to] sue without joining the persons for whose benefit the action is prosecuted." (Id., at p. 246, 28 Cal.Rptr. 548.)