1. Peter Pettigrew sorted into Gryffindor
    Peter is the opposite of everything that Gryffindor stands for
  2. Fred and George give Harry the map because they don't need it anymore
    Uh what? Who just passes down that kind of treasure when they're trying to keep up their reputation of Greatest trouble makers in the wizarding world
  3. Sirius thinks Peter Petigrew would be a better secret keeper for the Potters than he and convinces James to switch to Peter instead
    The dude's animargus is a rat. That wasn't enough of a clue?