(1) In any suit or proceeding against any member of the Coast Guard for any act done by him in pursuance of a warrant or order of a competent authority, it shall be lawful for him to plead that such act was done by him under the authority of such warrant or order.

(2) Any such plea may be proved by the production of the warrant or order directing the act, and if it is so proved, the member of the Coast Guard shall thereupon be discharged from liability in respect of the act so done by him, notwithstanding any defect in the jurisdiction of the authority which issued such warrant or order.

(3) Notwithstanding anything contained in any other law for the time being in force, any legal proceeding (whether civil or criminal) which may lawfully be brought against any member of the Coast Guard for anything done or intended to be done under the powers conferred by, or in pursuance of any provision of this Act or the rules, shall be commenced within three months after the act complained of was committed and not otherwise, and notice in writing of such proceeding and of the cause thereof shall be given to the defendant or his superior officer at least one month before the commencement of such proceeding.