So Ive had this happen a few times and couldn't find an answer, but anyways: Creepers will sometimes explode on their own. Not like spontaneously, but it usually happens when I accidently run into a group of mobs, then run away and ill hear a creeper exploding on its own but really far away from me and I was not within the necessary distance for it to start detonation. Could this have something to do with being angry at skeletons?