Factual error: Magnetic tape recorders weren't available outside of Germany during World War II. True the tape recorder could have been captured from the Germans, but, as it was "cutting edge" technology for 1941, it would hardly be likely to have ended up in a hospital office.
Revealing mistake: Dalek is escaping and enters the large room with the soldiers. He starts the sprinklers so he can kill them faster. When they show the dead soldiers they show some casings which were ejected from the soldiers' guns. The casings still have projectiles in them. If used, they would have been in magazines and would never fall out like they are shown.
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'.
Revealing mistake: When The Doctor travels back in time after being shot by the Dalek, falls down the stairs and tells himself that he has 12 minutes to live we never see either of the 2 Doctor's faces onscreen at the same time, and if you look at the hair on The Doctor that's dying it is completely different to Matt Smith's. That's because it is Gordon Seed, Matt Smith's stunt double.
Continuity mistake: When the three bride Autons attack Jackie, and they open their hands one at a time, it is clear that when the second Auton opens its hand, all three are already open. After it cuts to Rose, and back to Jackie again, the third one opens (even though we just saw it already open).
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 mistake: When Mickey closes the wheelie bin lid, he then finds the plastic stuck to his hands, he lifts his hands up and the plastic stretches like tar. If you look closely when he lifts his hands up for the first time, you'll see that a shadow of one of his hands is cast on his shirt, but there is no shadow of the strands of plastic stuck to his fingers. Additionally, when he turns around to pull away from the bin, he crosses the strands over each other, but they are still parallel in the following scene.
Plot hole: Those people created for medical experiments cannot run. In fact they can barely walk, so how come they can climb nearly as fast as Rose? What's more, when you see them climbing, they seem to have little ability to coordinate hand over hand. Even with the delay brought on by the cat-woman-thing, they should not have been able to keep up with her.
Plot hole: Davros said that the reality bomb would destroy all parallel universes. He fails in the Doctor's universe, but the Doctor said in an earlier episode that every decision creates a new parallel universe, like if Donna had walked out of the TARDIS with Jack, Rose, and the Doctor. She wouldn't have imbued herself with Time Lordness, so Davros would have succeeded. This means that all the universes, including the Doctor's one, should have been destroyed, because if the Reality bomb only succeeds in one universe, it would destroy all the others as well.
Revealing mistake: The 'earthquake' that takes place in this episode results in CGI-created cracks in the pavement that are very unconvincing. They do not appear to displace anything and - in a related continuity error - the cracks disappear in shots taken from ground level (the cracks are only visible in high-level 'looking down' shots.
Factual error: Ida, the science officer, says that the planet is in geostationary orbit around the black hole. However, the word "geostationary" applies very specifically to objects orbiting the planet Earth. Since a black hole is a type of star, this planet's orbit could be described as astrostationary, or even just stationary, but definitely not as geostationary. A science expert on an interstellar mission wouldn't make this mistake, and she wasn't dumbing things down, either, since "geostationary orbit" is already a pretty obscure topic for people unfamiliar with space technology.
Continuity mistake: When the Doctor and Ida descend into the core of Krop Tor, the screen charting their progress shows 39% Oxygen. After cutting away to an overhead shot of the two, the camera cuts back to the same descent display, only now the oxygen percentage (which has been descending constantly all this time) is at 42%.
Continuity mistake: Near the beginning of the episode, the Doctor and Jack destroy a Dalek who is inside the Tardis and you later see it when the Doctor, Rose and Jack come back into the Tardis after talking with the Emperor Dalek. Yet later when the Doctor is sending Rose home, there is no destroyed Dalek.
Other mistake: When The Doctor tells the Atraxi "Oh, you're not the first lot to have come here, there have been so many," one of the monsters shown from their scan of Earth are a group of Ood. Even if in one of their uprisings they attacked the Earth, it would have been in the far future. The Doctor had no encounter with them on Earth, and he knows them to be peaceful, so why would they be amongst the aliens who have threatened the planet? The only Ood who has been to Earth at this point is Ood Sigma, and he didn't come to attack.
Factual error: One of the programs on the new television set is "Animal, Vegetable, Mineral?". In 1953 this quiz show was broadcast on Thursdays. But, it's the eve of the coronation, which makes it Monday the 1st of June. "Animal, vegetable, mineral?" wasn't on that evening.
Continuity mistake: As the scarecrow-soldiers advance on the school to do battle, the scene cuts to Sister-Of-Mine, looking out from a school window. There is heavy rainfall outside. When we immediately cut back to the advancing scarecrows, it is a cold, clear night.
Plot hole: In "Aliens of London" it is established on a 'missing person' poster that Rose Tyler is approximately 19 years of age in March 2005 (The poster says 'missing since 6 March 2005'). This means that she must have been born prior to March 1986. However, in 'Father's Day', which is dated 7 November 1987, Rose is still a baby in her mother's arms - but she should be a toddler aged approx two.
Revealing mistake: When the Alien spacecraft crashes into Big Ben, it is obvious that the shot has been reversed/flipped around. Look at the Roman numerals on Big Bens's clock face: They should read (clockwise from the top) XII, I, II, III, and so. Instead they read IIX, IX, X, etc.
Continuity mistake: When Rose presents her mother with the Bazoolium, she's holding it in her left hand. When the view switches to look at Jackie, it shifts to Rose's right hand and then immediately back to her left when the view restores to the original vantage point.
Revealing mistake: 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.
Visible crew/equipment: After Miss Kizlet enters her office to find the walking base station Doctor sitting at her desk, as she walks around the motorbike lying on the broken glass, when this 'Doctor' says, "Yes, those still with bodies to go home to would be free," we can see the moving reflection of two crew members on the surface of the motorbike.
Continuity mistake: After Strax hits Clara with a newspaper she comes downstairs and he asks her if she needs anything. She asks for water and he places the bucket of mop water on the table in front of Clara. They have a conversation about the water and at the end of the conversation Clara looks at her newspaper and the bucket has disappeared from the table in front of her. Neither of them moved it.