Factual error: Emergency Service vehicles in Cardiff (indeed, throughout Wales) have their signs in bilingual English/Welsh. So the police cars and ambulances seen in this episode should have 'Heddlu'/'Police' and 'Ambwlance'/'Ambulance' bilingual logos. However, the police car seen after the earthquake has its label in Welsh only.
Factual error: When Rose gets the message there are two things wrong with what you see on the phones screen: firstly on the top right of the screen you can see the icon for mute even though you heard the beep, and secondly that screen is for when you type in the number you want to call (text), not the screen for receiving a text.
Continuity mistake: At the end of the episode, Donna piles suitcases in the Doctor's arms in preparation to leave with him in the TARDIS, and places a striped hat box on top. The bags stay that way for a while as the camera cuts back and forth between them, and you can see the stack of luggage as the camera films the Doctor from behind. Then, as soon as the camera cuts back to the Doctor's face when Donna leaves to give her mother the car keys, suddenly he has one bag under his arm and another in his hand, and the rest of the bags are on the ground with the hat box stacked neatly on top. In addition, when the scene cuts from Donna closing the hatch of her car to her and the Doctor standing by the TARDIS, a large floral-patterned suitcase has appeared, which she was not shown removing from the vehicle. (00:43:15)
Deliberate mistake: When the Doctor visits all his recent companions before he regenerates, he goes to a book signing of A Journal of Impossible Things, written by Joan Redfern's great-granddaughter. When she is signing the book for the Doctor, you can hear the scratching effect from the pen but you can see that the pen isn't touching the paper. (00:59:50)Professor Lazarus
Factual error: When introducing himself to the Toclafane, President Winters refers to himself as "President-elect of the United States of America." President-elect is the title given to the victor of an American presidential election who has not yet been sworn in, between early November and January 20. This was a mistake on Russell T Davies' part, as he was under the impression it was a longer, formal title for the American president. (00:37:40)
Factual error: When the Doctor regrows his hand during the swordfight, he says that he can do this because he's still within the first 15 hours of his regeneration cycle, and there's still residual energy in his body. However: In both this scene, and the episode's opening scene, when the TARDIS arrives in London, it is full daylight. The episode takes place on Christmas Eve and Christmas Day, 3-4 days after the Winter Solstice. London, at 51°N latitude, has a night longer than 15 hours at that time of year, meaning the Doctor should have been out of luck.
Continuity mistake: When the Doctor and Clara are on the rooftop terrace, there's a distinctive design on the Doctor's bow tie, but when he's in the coffee shop the bow tie's design differs, and when he runs outside to ask if Clara's okay it changes back, then it changes again when he's in back the shop. Additionally, when the walking base station Doctor uploads Clara it's wearing a bow tie, and its design also changes on the motorbike and in Kizlet's office.Super Grover
Continuity mistake: While Clara shouts, "I don't know where I am," over and over, the Doctor sonics his way into the house. When he kneels beside Clara, then notices the 'girl' on the stairs and stands up, in the shots facing him we can see that the young actress stands on the step facing the stairway (note her legs), with her hand at her side, but in the shots facing the girl she stands facing the door with her hand on the banister. (00:14:20)Super Grover
Continuity mistake: After the Doctor yells at Handles for putting him on the Dalek ship, the Doctor grabs him and carries the head with his right arm, then switches the head to his left arm. However, in the close-up as the Doctor asks, "What does this question mean?" we see Handles is back on the Doctor's right arm, but next shot as the phone rings, Handles is carried on the Doctor's left arm again.Super Grover
Continuity mistake: When Clara and the Doctor watch the lights going out, they first stand in front of the chair, but when the Doctor notes that some planes have WiFi, they stand behind the chair. That chair switches from in front of them to behind them another couple of times. (00:24:00)Super Grover