I'll agree with this, he probably should have removed the cartridge and utilized it via direct contact given the proximity.
Hey looky there - a training/doctrine consideration.
I'm willing to listen to suggestions you would have.
Since you asked - my understanding is that he had requested backup, but did not wait for it to arrive before getting the kid out of the car. By then, the kid was obviously unruly and an asshat.
I do not know how urban or rural that place is, but around here, waiting for backup would not take an unreasonable amount of time. Plus, the kid won't identify, so the traffic stop can continue as long as it needs to. (Even ignoring the failure to identify as a separate RAS/PC.) It was a stalemate, sorta, but the officer has all the time (and overtime) he needs. "Kid, you're not free to go until you identify. And, when my backup gets here, we're getting you out of the car anyway."
Let me be clear about what I'm NOT saying: another officer does not guarantee the kid survives the encounter.
What I am saying is that with another officer's help at an earlier stage of escalation, THIS officer may not have felt the need to for the final escalation. One officer on his back couldn't keep the kid down, but 2 would've been much more difficult.
ETA:
IMHO, this needs to be addressed at a training/policy/doctrine level, if for no other reason than it is likely to become more frequent. No indication that this kind of cop block stuff is getting LESS popular.