When Mary enters Mr. Murphy's back room there is an old photograph hanging on the wall, but in the previous shot as she moves toward the room the photograph is not there.
Harvey takes some bananas to the table to make his sandwich, but there is already a sliced banana on the table.
When Steve takes hold of the rope holding the dummy prank intended for Georgia the rope is slack, indicating there is nothing heavy on the other end and the dummy would not drop.
Mary's adoption papers state her year of birth to be 2014 making her 8 not 17/18 as she is.
When Mr. Murphy locks the door and turns around you can briefly see a boom mic in the bottom left corner.