No person who acts under a power of attorney of a principal in the armed forces of the United States, or of a principal whose duties in connection with any service in which the armed forces, as defined in section 27-103, are engaged involve his or her absence from this country, shall be liable for any such act on the ground that such principal was not alive when such act was performed if such act was performed in good faith and without knowledge of the death of the principal. All such acts shall have the same force and effect upon title and in all other respects as though the principal were alive.