aggressively passive
When someone goes out of their way to be passive about things, or to just not be involved. Often, getting involved wouldn't inconvenience them, but they just don't care about that. They want to ignore it and be on their way.
John: That person was calling out for help, and you ignored him.

Jill: Yep.

John: But why?

Jill: Haven't you heard? I'm aggressively passive.