The person in charge of any aircraft for the time being within the territorial limits of New Zealand, and any person acting under his or her directions and on his or her behalf, may possess, import, export, and, in any case where the administration of a controlled drug is expedient for the purpose of treating a sick or injured person in an emergency, administer to that person any controlled drug authorised or required to be carried on the aircraft by any law to which that aircraft is subject, and lawfully supplied to him or her.