I have two things to say regarding this situation:
#1) Yes, in a Pre-Hospital situation an EMT is allowed to do more than an RN. Only by a hair though. An RN in a setting where he/she is not at work is limited to BLS. Airway, Breathing, Controlling Bleeding/Circulation, she cannot give any meds because there is no doctor there to supervise and give orders. Even a basic EMT can give Aspirin, Epi-Pen, Nitroglycering, Oxygen, and Charcoal. In an emergency pre-hospital setting that LPN/RN etc don't mean crap. I am an EMT/Fire Fighter with a volunteer department. When I am responding to an emergency I can only to BLS, no IV's, no Intubation, no ACLS. While it can be frustrating I know and accept my limitations. I do use my ACLS knowledge to be sure the paramedic has whatever he needs next in his hand before he can even ask for it. I can also tell you that EMT's/Paramedics have had very bad experiences with the Pediatric Office Nurse running up to the Multi-Car pileup screaming "I AM A NURSE" and have no clue what to do and not realize that unless she is prepared to do CPR there is not anything she can do in the pre-hospital setting. Same as the proctologist running up yelling "I AM A DOCTOR". It is just a completely different scope of practice.
#2) Now, unless that EMT was WITH the ambulance or first response team that was ON DUTY he was just a bystander - first responder. He was not practicing EMT that was being covered by his Medical Director with no established Duty to Act. As such he had the exact scope of practice that a bystander - nurse had. Couldn't do anything that you couldn't do. At this point you were just two profesionals disagreeing on a course of action. You both were at the same level and do not outrank each other. If he was the EMT on duty and this was officially his patient then YES his orders would have outweight your concern, but since his name would have been on that run-report he would have been responsible for the patients aspiration pneunomia. You know how pissed we get when a family member/friend who is an EMT/Nurse/Doctor tells us how to do our job, its kind of like that.
#3 (Yes, I reallize I said I only have 3 things to say) COMPROMISE!!!: There were two of you. How about one log rolled to clear the airway while the other held on to the head and maintained inline stabilization of the c-spine. That would be what we would do if we had to clear airway without suction in an emergency with a possible cervical injury.
My 3 cents, have a good night everyone, and stay safe out there.