I've seen it happen throughout my life.
My brother could say the meanest and cruelest things to anyone and then be excused for it with one question: "What did you do that made that happen?" But if someone said something to him that was mean and cruel in retaliation then that person was gong to go to Hell with my mother at the Helm of Charron's skiff.
The kid in school that loved to tell stories about the other kids, true, pure falsehood or exaggeration that would cause other kids embarrassment would cry his/her little heart art the second the same was done to him/her.
The kid who stole my homework thought nothing of defending himself with the diversionary tactic of clling me a "narl" or a "tattletale" which were social crimes comparable to theft. I would suffer the loss of homework and bear a title which suddenly absolved him of all wrong doing. But when someone would "borrow" his gym equipment he began barking about cutting off hands like they did in the Bible.
What is good for one should be good for the other, yes? Certainly that is the case in all good things that happen. It also should apply when standard corrections do not change poor behavior. I liken it to the biter that I had in my charge as a young day care provider. Timeouts didn't work. Withholding snacks was not an option. His parents grounding him didn't work. And of course as a state licensed care provider corporal punishment is out of the question. Months of biting. Months of the other kids learning fear and displaying early PTSD made us get creative. He needed a dose of his own medicine. And it worked.
When it is adults who are doing the dirty work it is not so easy. The very first person to break the rules is usually the one who raises the biggest stink when the other person retaliates because normal channels never work. The rule that is broken is the one that is used as a shield to protect them from the fate inflicted upon others. The husband that cheats is going to cite his vows and call his wife a whore if she goes out for a drink with someone from work. Sure the wife shouldn't go out. But if all other entreaties to get him to behave fail then why not have a drink, incite some payback to elicit empathy?
The gossipy coworker who does not hesitate to dish on everyone else and fails to yield to corrections administered through proper channels is going to be the one who cried foul the loudest if it happens to him/her.
We live in a world of double standards that let perpetrators prevail through the use of a double standard. Sure, we say what is good for the goose is good for the gander. But, Oh Sheila! The second that gander gets his goose cooked there is war and the shield of choice is always going to be Inciting the Rules that the perpetrator broke in the first place.
The Double Standard is a fine piece of manipulative art. It's employment makes a Victim into a perpetrator and a perpetrator a free man with the ability to commit the same crimes against a person's character. The reason the retaliation doesn't work with adults is Ego.
Kids don't have such a steadfastly defined Ego as adults. It is possible to inject empathy into a child before they reach a certain age. And if anyone in the field would keep committed to that Certain Age I would tell you what it is. As soon as identity is set, Ego is established the jig is up. Adults can not be changed through an easy trick like biting back when first they bite.
The double standard is insidious.
I hate it.
I feel powerless against it. The only protection against the manipulator that uses double standards to protect themselves during the committing of unfriendly acts is to avoid the manipulator at all costs. I have done that with everyone who could not be reasoned with. It is my standard defense for dealing with EVERYONE who manipulates. While I have actively chosen to refuse the way of the victim I sometimes still feel like one; especially when someone that I would never have thought capable of doing so and have let near me does it. I know that old ones. It's the new ones that always surprise me.
I wish there was one Gold Standard of Human interaction. But there is not.