The person tested may select and allow any physician, registered nurse, or person licensed in a clinical laboratory occupation under § 321-13 to withdraw blood or have any person administer a test or tests in addition to any administered at the direction of a law enforcement officer. The results of the additional test or tests may be used as provided in § 263A-5. The failure or inability to obtain an additional test by a person shall not preclude the admission of a test or tests taken at the direction of a law enforcement officer. Upon the request of the person who is tested, full information concerning the test or tests taken at the direction of the law enforcement officer shall be made available to the person.