Once again, a paramedic working as an EMT has to follow EMT protocols.
Using California as an example (because that's where I'm most familiar with), an EMTs scope of practice includes the ability to "evaluate the ill and injured." If I deem that a cranial nerve exam, for example, is indicated. Please tell me how I would be violating my protocol by conducting a cranial nerve exam? How about percussion? Rinse, wash, repeat with essentially all manual exam techniques. In fact, I could argue that I could use a lot of exam tools. If I'm, as an EMT, am empowered to "evaluate the ill and injured" and am properly trained in using an otoscope, is it really against my scope of practice to use one?
Even with strict protocols, there's still a fair amount of judgment that can be utilized. How is using a paramedic level of knowledge violating EMT protocols? Alternatively, is every action where you work dictated by protocol?
There is a vollie in NYC, where an actual MD works. When he does so, he acts as an EMT, not an MD, he has not authority above anyone else or to do anything else.
If he decides to go full physician, including taking on malpractice liability, there's absolutely nothing legally stopping him. If he wants to equip himself with a manual defibrillator, there's absolutely nothing stopping him. A license to practice medicine does not end at the hospital or ambulance's doors. I can, however, see liability and maintenance of drugs and equipment, and staffing concerns (if he is acting as a physician, then does he still count towards the minimum number of EMTs in states other than NJ?) as valid reasons to restrict the tools available.
Additionally, ask him if he limits his differentials only to those listed in an EMT text book, or if he uses his medical education to help make judgment calls. I'm also willing to bet that, when push comes to shove, he would take charge in a second if another provider started to engage in malpractice. However there's very little to legitimately foul up on a BLS unit. Seriously, in the grand scheme of things, there's very little to screw up on most patients.
Finally, ask him what he'll do when presented with a field birth of a baby with shoulder dystocia. I'm willing to bet that he wouldn't blink at placing the patient in McRoberts, or applying suprapubic pressure or performing an episiotomy if need be. By virtue of being a licensed physician, he has the legal authority to do those. The only question is, will he and at what cost?