Why such severe hostility towards Tyler

Were the others always hostile towards Tyler before the peeping Tom incident? Also, some of them had crimes that were worse, yet treated Tyler like crap and reacting towards him by throwing rocks at his window and violence and threats of violence. Also, why not at least include him in the predicament as there was a lot to lose if there actions are found out. Alienating someone who had information on all of them is not a good idea. Technically with the way they treated him, he had nothing to lose and out of revenge turned the tapes over. He may have been punished, but so would many of the others. We know that does not happen and that he has a bit more......hostile plan for all of them, but someone should have thought of that possibility. Hell, he even suggested making someone a scapegoat yet they still acted like he didn't matter. They didn't have to be nice, but at least try to not rattle him to the point they did.