Except as provided in Section 950.4, a cause of action against a public employee or former public employee for injury resulting from an act or omission in the scope of his employment as a public employee is barred if an action against the employing public entity for such injury is barred under Part 3 (commencing with Section 900) of this division or under Chapter 2 (commencing with Section 945) of Part 4 of this division. This section is applicable even though the public entity is immune from liability for the injury.