[DaBackpack]

It might be easier to navigate if we're more precise about the issue.

Personally, I don't really find holistic markers like "good person" and "bastard" super useful when it comes down to it. Your friend might, in general, be "a good person." When we say ACAB, it's a statement that "being a cop" is de facto a negative character trait. There is no way to spin "being a cop" into a consistently positive trait. This is at the heart of ACAB.

Your friend might donate to charity, volunteer at pet shelters, and be a community leader. These are positive traits that reflect well on him. But at the end of the day, none of these things "cancel out" his being a cop. People can be both good and bad.

The question you should be asking isn't "is there an example of a cop that I think is a good person?", but rather "is there a good person who I thought was good BECAUSE he was a cop?"

"He seems like a sweet guy, but he's a police officer." This right here illustrates this nuance. "He's a police officer", in this case, is positioned to form a juxtaposition with the clause "He seems like a sweet guy." The cop-ness DETRACTS from the original premise of "He seems like a sweet guy." That is ACAB.