First off, no one is going to be applaud his cleverness for starting a rumor that they serve road kill for lunch. While he smiles along evilly at the prospect of people being revolted by the possibility, what the moron doesn't see is that they're going to be miffed by being tricked so some jerk can have fun at their expense and not want anything to do with someone as crass, selfish and unconcerned with their opinion as he is.
Second, he doesn't especially want to have to admit that the people in charge of the camp aren't cartoon characters with their heads shoved up their asses. My initial reaction to his giddy discovery that a hole had been chewed in the wall of the girls' shower was to assume that if he knew about it, it was pretty much guaranteed that his calling his bunkmates' attention to that followed the camp director's discovery of same by at least three hours. If Lynn hadn't wanted so very much to give Elly a reason to want to throttle Michael because she can't see the kids who dare him to do stupid things, she would have had him moan "Aw, MAN!!!!" because it had been boarded over by the time they got there.
Third, of course, is having to remember that Mike doesn't learn things from his mistakes because doing so would mean admitting that television and movies lie to him about what life is like. If he were to admit that, he'd have to look back on his life in regret and despair because of all the wreckage left behind by his bad case of cathode ray poisoning.