In WV the firefighters run the scene. Cops assist. We had a medic get threatened with arrest by a state trooper when he interfered. And yes, firefighters can have you arrested.
I believe this is the case in most jurisdictions. I am thankful there are no interstate highways in the village where I am a first responder. Our one state highway is 45 MPH which keeps damage low to moderate in collisions.
I think that is also true in Virginia.