Factual error: In the opening shot of this episode, we see the Earth from space. The camera then zooms into Western Europe, the UK, London, then into Rose Tyler's flat, where a jump cut to an alarm clock shows its 7:30am. But look again at the start of that sequence: it shows that it's daylight over the UK - and over the USA. This is of course impossible. When it is 7:30am in London, it is 2:30am in New York, as Eastern Time is 5 hours behind UK time. Usually, in New York, at 2:30am it is not daylight because it is the middle of the night.

Revealing: The Doctor and Rose locate the "metal" hatch that leads down into the "Plastic's Leader" blob. Watch carefully after the Doctor removes the "metal" hatch and moves it aside. The entire hatch "pops-up" a second later. This is because it is plastic and it was suctioned to the floor.

Deliberate "mistake": The final Auton attack in this episode is supposed to take place in a busy London street, but it is a pedestrianised area, and several shots reveal this. For example, there are no road markings visible, no apparent distinction between pavement and road, and a bus stop appears to sit in the middle of the 'road'.