Not sure about you but if I was dazed and confused after a car crash and a cop repeatedly smashed me in the head after trying to get out of my smashed car I’d be described as “seriously violent, aggressive, and uncontrollable” and need to be tased too.
Assuming it is a beer bottle and the cop was trying to collect evidence which I think the body cam would have been plenty. A “ here let me hold that for you whilst you get out” and after extracting himself “you’re under arrest, please put these handcuffs on” would have worked much better.