Hmm - I feel like there are levels to that, though. Surely
the date on Rory's nurse badge, and Amy's age as determined by Starship UK may have something to do with the cracks? Or maybe they're just production errors. Also all that cryptic 'silence will fall' stuff that Prisoner Zero says...
All stuff I only really get to spot or think about when rewatching an episode, that starts me anticipating what might be coming up in the 'arc'. I'm really enjoying it all anyway, I hope the episodes keep on being as good as Saturday's.