I'm sorry but I see this completely different. Maybe it's just a little law enforcement training...
About 1:30 into the YouTube video you see the State Trooper addressing the EMT (actually looks like the EMT in the pax side of the amulance). It is rather emphatic and authoritative, but last I checked, law enforcement officers are figures of authority in our society.
In fact, the EMT moves from the cab of the ambulance back to the patient area and past the State Trooper with no contact, only verbal exchange stating he was placing the EMT under arrest. Up to this point, the Trooper has exercised retraint in the use of physical or deadly force.
Next we see the EMT exit the patient compartment and basically get in the face of the two Troopers. The EMT is being confrontational. I don't know of a single LEO that WOULDN'T view that as a threat.
Folks, this right here was the turning point and what gave the Trooper the right to initiate the action he did.
Plain and simple, you don't get in a cops face, you don't run from the cops, you don't turn and face the cops with a random or unidentifable object in your hand. Basically, when a cop tells you to do something you do it. Of course there are personal safety tips -- do it in a public area, dealing with non-uniformed individuals who identify themselves as LEOs, etc.
As soon as the EMT got in his face though the Trooper had all the legal right he needed to subdue the guy. The size, demeanor, and proximity of the EMT created Ability, Opportunity, and Intent.
As soon as the Trooper begins to subdue the EMT with a standard wrist lock and arm bar to restrain him against the ambulance to cuff him, the EMT retaliates and RESISTS ARREST. In fact, he goes so far at to elboy the Trooper in the throat. A struggle ensues, and the officer, dealing with a sizeable threat, uses techniques he was trained with (yes Virginia, choke holds are part of that training) to eliminate the threat.
Finally, the "choke" the officer used hardly had any tension behind it, indicated by the capability of the EMT to basically stand normally, point for the camera to the Troopers hand, and then continue to speak.
Guess what, you also don't resist arrest. The Trooper exercised EXCELLENT restraint, even so far as to release any tension from the choke grip almost immediately. He controlled his adrenaline rush very well.
I don't give a shit if the EMT did or didn't commit a crime. There were plenty of witnesses and if he was on the up and up, he would have been cleared and we'd be talking about wrongful arrest, not "police brutality."
And lastly, let's get one thing real clear...the EMT got placed in a subduing choke hold because he RESISTED ARREST. NOT because he passed cop car. He may have been pulled over for that, but if he played his cards right, the choke hold never would have happened.
The EMT just got introduced to the responsibility for his actions.