How do you figure you just have to be an agreeable player more often than a toxic asshole to not be punished? Being alright in 3 out of 5 games does not change the fact that in 2 you deserved to be punished. There is no magical karma here that builds up and lets you cancel out any assholery. For an analogy, if you are accused of stealing 100 phones but turn out to be innocent in 99 of those cases it does not make that one theft you were actually guilty of disappear. You still get punished for breaking the law there. It's the same with Tribunal. You broke the Summoner's Code which you are obliged to follow in those 2 cases. You are punished for this transgression, and acting OK in remaining 3 cases is completely irrelevant.