If you watch closely you can see the guy walks away from the cop and the cop following to complete the contact/investigation/whatever.
Then the guy physically pulls away from the cop and started to push the cop. It was then the cop shoved the guy. You me, anyone else wouldn't have fallen. This guy did.
Not the best contact but the shove of the guy was (relatively speaking) minor and clearly not intended to make the guy fall down.
It's what I saw.
How about the slap in the face after he had fallen down?
Yeah, he didn’t mean to slap him hard to the ground either. A complete accident.
/s
So basically the cop was trying to help the guy by knocking the piss out of him...