And in making you angry, they are responsible for their actions. That's the point. This is not a difficult concept. We can all affect others to do good or to do bad. If we affect them to do bad, by our own bad actions, we bear some guilt for that action.
Are you saying that a man who offers a married woman who can't feed her kids $3000 for sex bears no responsibility for her sin? Of course he does.
You are confusing shared guilt with mitigation. How can you possibly argue with the premise (I'd say fact) that treating another person badly can result in them treating you badly, and when that occurs, both share in the responsibility. Is this realization not how most disputes are resolved?
Is this always the case? Of course not. Some people do bad things all by themselves and use whatever they can to justify it.
Good luck on your quest...you’re trying to reason people out of mindsets they didn’t reason themselves into.