Near the start of the episode, the doctor unstacks and then re-stacks a tower of 3 cardboard boxes Donna is holding. He starts by removing two boxes, and then replaces one of the boxes before turning around, intending to walk away. In the next shot, the other removed box has inexplicably reappeared on top of the stack.
When the Doctor and the Noble family go through the second attic, the same boxes of Christmas decorations that were in Donna's are in the same place.
Bingham's use of a wheelchair does not automatically indicate that she is paraplegic, as many non-paralyzing disabilities require the use of a wheelchair. The actress Ruth Madeley has spina bifida.
In the opening, the Doctor does not lock the TARDIS when he leaves, just letting the door swing shut behind him. At the end, he has to unlock the TARDIS to regain entry.