I like both of those possibilities, really. I think number one is the obvious one, and so far all the obvious answers have been right, but I'm kind of hoping number two is the correct answer. (Though of course there's always the possibility that there's just one big time loop, and the reason that Hiro knew to go to the future to tell Peter to save the cheerleader is because Peter told him that Hiro from the future said that the cheerleader needed to be saved).