Visible crew/equipment: When Guarino is being taken away by The Hunter, you can see the rope used to pull him in the upper right corner of the screen. (00:46:05)
Revealing mistake: When Jemma enters the headshrinker's laboratory, there is a table with three heads on it each encased in glass. When it goes in close-up on the middle head, you can see that the table has a hole where the actor can slip in his head.