Hope this hasn't been taken yet: When the bad guy is finally caught (like very bad, killing innocents type bad) and they don't kill them but the writers kill them. It is the literary version of revenge for the falsely altruistic audience. So the heros were going to allow this villain to continue killing "so we aren't as bad as them" but the writer kills the villain through chance or accident. This gives the audience the poetic justice high. Either step up and show you can wear the big kid pants and end the evil guy forever or just admit that the evil guy wins because no one is willing to do anything about it. But killing the bad guy by chance just to give the simpering audience a way to see them eat it without any guilt, that is just cheap pandering.