If it thereafter appears to the satisfaction of the appeals board that the insurer has assumed the liability for compensation, the employer shall thereupon be relieved from liability for compensation to the claimant. The insurer shall, after notice, be substituted in place of the employer in any proceeding instituted by the claimant to recover compensation, and the employer shall be dismissed therefrom.

(Amended by Stats. 1965, Ch. 1513.)