I give police the benefit of the doubt to take out someone who is showing them aggression, because the police officer has weapons on him that can be turned on him and the general public if the perp were to get the jump on him.
Which is why officers are trained in retention of those weapons/devices.
Police can't wait for the guy to throw the first punch before they act.
Not always, no, but you can't treat every damn person like they are a 2 time felon either, and get pissy b/c somebody called you out on being slow to get there.
Cops should have apologized for being late, explain to the guy they were on another call, and had to finish there first, and show interest in the guy's problem.
The dude was just assaulted by his roommates, and had his shite thrown all in front of his residence, and it took the cops almost an hour to get there, he's probably a little upset which is understandable.