An emergency medical technician-basic, emergency medical technician-intermediate, or emergency medical technician-paramedic may perform medical services that the technician is authorized by law to perform in nonemergency situations if the services are performed under the direction of the technician’s medical director or cooperating physician advisory board. In nonemergency situations, no medical director or cooperating physician advisory board shall delegate, instruct, or otherwise authorize a technician to perform any medical service that the technician is not authorized by law to perform.