As things are in the video (and without a wider context), the use of force of this magnitude is completely misplaced.
I agree 100%.
Wider context is needed. You tube videos can easly be edited WRT timelines, when they start and stop, to create a biased opinion.
A 13 second video of a cop striking a man who has his hands in his pockets could very well be from a 2 minute and 13 second video of said man pulling a knife on a police officer and stabbing them thrn running away, hiding trying to blend into a crowd then when found has his hands back in his pockets saying "hey man I don't wanna fight".
He could have a pistol behind his back in a waist band or had previously been extremely violent.