You have pretty much said we should treat everything as the same. I'm glad you are not in charge of the law, otherwise all defences will be muted by 'a similar thing has happened before and they were found guilty, so that means you are guilty'. That is essentially what you just said. You would pretty much ban any form of violence against dogs by police, even if it was in self-defence. You cannot treat everything the same.
Those two are different events by two different people, involving two different dogs, which could be under two completely different circumstances. You cannot judge one incident based on another.
Did I not already say that they 'may very well be guilty' or something to that extent? Yes, I did. But I'm just not into jumping to conclusions just based on a segment of footage. There are quite a few videos (not all) like that in this thread that only show the police aggression, but no moment before that.