Legalities: At least in Calif.,without an order, even in the form of a protocol, a RN cannot give oral medication. An OTC topical like ABX oint is a fencestraddler, and if there is a bad side effect (allergy?), someone can get in trouble. Where can an EMT do something a pharmacy-trained RN can't?
Situations: you are doing standby at the company picnic and someone has a headache or a muscle pain from an activity. Or they have indigestion from the rancid egg salad. They probably did not bring anything, or its been sitting in their car cooking at 135deg F for years.
The kicker for these cases is if you are doing SOAPIE documentation, you are supposed to truthfully re-asses and describe the outcome of your treatment.
Spare me.
Oh, by the way...make sure that indigestion isn't an MI or acute food poisoning, the muscle ache isn't a stree fx, and that headache isn't an incipient CVA or dehydration.