Continuity mistake: When the Doctor uses his sonic screwdriver on the glass partition in the Torchwood Institute, cracks radiate out in a star pattern, meaning the glass will break into pointed shards. When it does break, it breaks into cubes, like safety glass. (00:29:30)
Revealing mistake: When the Doctor is being rolled down the stairs whilst he is strapped to the chair, it is apparent that in the wide shots, it is a dummy in the chair and not the Doctor. In the wide shots, the Doctor is sitting virtually still and motionless, but in the closer shots, he is fidgiting.
Continuity mistake: When the Doctor is at the Tower of London with Amy and Kate, he claims he needs some air. When Amy follows him she follows him twice, in two different shots. The first time on 'ground view' walking and the second time on 'above view' running. (00:21:20)
Revealing mistake: The pyrotechnic mortars used in the destruction of the Family's ship are visible in the shots leading up to their detonation. As the Family run from their ship through the field, the mortars are visible against the branches behind them. Shortly afterwards, they detonate, creating the illusion that the invisible craft has exploded.
Continuity mistake: When Timothy opens the watch into the girl's eyes, Jeremy Baines shouts "Time Lord", then a few seconds later; "What are we waiting for. Attack!" There is then a shot looking down on the scarecrows, Jeremy and Jenny. If you look closely at Jeremy Baines, it's a different actor playing him. (00:16:20)
Factual error: The all important date of 26/06/2010 and it ticks over on Amy's alarm clock right at the end of the episode. However it shows 11.59 AM and flicks over to midday (12.00PM) the next day. The date should've stayed on 25/6 or, as I suspect was the intention, the clock should've read 11.59 PM and then ticked over to 12.00 AM thus changing the date correctly. (00:41:00)
Other mistake: As Amy, River and The Doctor enter "the Underhenge" River says "More than just a fairytale." This is a reference to The Doctor saying pretty much the same thing to River at the end of S5 E5 when she says she will see him again "when The Pandorica Opens." This moment has not happened for River yet, it is still in her future. So how can she "call back" to it? (00:11:48)
Factual error: Colonel Mace says the Sontaran ship is orbiting 5,000 miles (8,050 km) above the Earth. However, in shots of and from the ship in both this episode and "The Sontaran Stratagem", the Earth appears far too small for the ship to be that close, with the ship's true distance appearing to be well over double that. (00:08:34)