Just a guess, but I would suspect it goes something like, "I'm just here to do my job, not to pass judgement for the protectee. That's above my pay grade. If I didn't do it, they'd just get someone else. Why should I give up my chosen profession just because someone else may or may not have done something wrong in the past?"

Writing it out like that, it almost makes sense. I'm surprised I have never yet gotten a mysterious job offer.