If either the employee or the employer brings an action against such third person, he shall forthwith give to the other a copy of the complaint by personal service or certified mail. Proof of such service shall be filed in such action. If the action is brought by either the employer or employee, the other may, at any time before trial on the facts, join as party plaintiff or shall consolidate his action, if brought independently.
(Amended by Stats. 1980, Ch. 582.)