Is Shaco's passive a case of "toxic, but permitted"?
Think of Backstab this way: Do you stand your ground and die, or run and die faster? Pretty lose-lose with confusing counterplay. And due to it being so wonky, you don't actually know if Backstab will apply when he hits you from the SIDE.
Yet Riot seems silent on whether or not this passive is something they want to keep or not.