Wait wait wait, something bugs me about that guy on the toilet who just fell apart after you take the code from him. It means he was either attacked with savagery enough to tear ligaments and (at the very least) unhinge joints but somehow left him in a perfect sitting position as opposed to in bits on the floor...or the zombies killed him, tore him up, and then posed him on the toilet for as yet unknown reasons. Not too implausible as the one zombie we saw was apparently holding a knife, indicating intelligence enough to use tools.
Zombies that are not only smarter than average, but have a twisted sense of humour...this game just got a whole load creepier.