I’m sorry to have used a phrase that brought back painful memories. I think it’s a phrase that, as you point out, can certainly be used as a disingenuous justification for simply ignoring your responsibility to do the right thing.
The older I get, the less I am inclined to “let stuff slide.” Abusive people certainly take advantage of individuals who try to be peacekeepers.
Your other two examples are spot on too. “Telling the teacher” doesn’t do a dang bit of good. Especially when the teacher is too busy slipping off into the cloak room to take a shot before class.
Kicking kids out of the house the moment they turn 18 always struck me as abusive behavior as well. You’ve given me a few more directions to take my thinking. Thanks for the insightful comment!