Everyone should keep in mind the line between PK and Anti-PK is very blurred. Everyone has their own unique way of handling a player encounter. Some lean one way, some lean the other. There is no sure-fire way to look at someone and just say, "Yep, he's a PK" or "Oh yeah, that guy is an APK". It's often a matter of how far they are leaning to either side.
I could be considered a PK because if someone walks into my encounter and I deem them to be a threat, I'm going to be shooting first. On the other hand some could say I'm friendly because I don't exploit the weak. I don't kill bluesuits, and even help them if I can afford to. Would I fit into the PK or Anti-PK category? The answer is neither, everyone is unique in their dealings with other players. Stop trying to see things in black and white.