There are cases where it does hold. Trivially, if the wrongs are vastly out of proportion, someone is overreacting. For example, if you're fixated on your phone, don't look where you're going and bump into me, that's a mild wrong. If I respond by slapping the phone out of your hands and stomping on it, I've caused way more damage to you in retaliation.

But in the case at hand, I'm with you: An obnoxious statement designed to invalidate someone's complaint countered by another obnoxious statement designed to invalidate the previous one, thus defending the original complaint, is perfectly acceptable. The point isn't just obnoxion, but a counterargument.