This gaslighting is designed to appeal for to use the moral high ground to effectively limit the use of a precedent established by your enemies, the very people or ideological camp that set the precedent in the first place and used it flagrantly to their liking. It's a form of prior restraint to hedge their bets when they lose control. "we did it, but look at what they might do! You better not do it (too)! Or else then you're-the-bad-guys." It's kvetching and sour-grapes-as-a-fucking-insurance-policy against any opponent who gains the upperhand and might be raw enough to resort to turn-about-is-fair-play. I call it projective interference, because they project their worst behavior onto you in an attempt to interfere with any retaliation that might come about because of their very actions and tactics beforehand. The correct move is to call bullshit and fulfill their worst fears.