The difference is that nobody is defending that guy, whereas misconduct by these officers is being defended by some people as a political tactic. There is no conflict in saying both things are bad, and indeed we teach kindergarteners that two wrongs don't make a right.

There seems to be a clear difference between criminals doing shady things and the government doing shady things. It seems like a false equivalency to compare an incident where a random guy does something terrible to one where law enforcement is rapturing people into the night while wearing masks.

What is law enforcement if not just random guys in uniform?

If the same acts are/were committed (i.e. ditch the sex trafficking example because the .gov doesn't really do that) what makes their misdeeds not equivalent to those of the non-state actor?

The difference is that we have entrusted law enforcement with a monopoly on the legitimate use of violence and so we expect them to hold themselves to a higher standard to be worthy of the enormous power they exercise on our behalf.