Yeah, someone being shitty to you doesn't mean go you full-fledged shitty in return, it kind of proves your lack of trustworthiness to begin with. It's like Nazis being like "leftists were mean to me by explaining how my politics made me a Nazi, so I'm gonna show them by Nazi-ing even harder! They forced me to be like this!" It kind of betrays the argument that the reason you got that way was because leftists were mean to you.