Factual error: The Police motorcycle in front of the Olympic runner is an S registration, meaning it was registered in 1998. The episode is set in 2012, and there is no way the Police would have such an old vehicle on active duty.
Continuity mistake: After the scribble creature has been analyzed and found to be made of graphite, the Doctor takes out a pencil and erases some of it to confirm this. The next time the graphite ball is seen, the erased area is gone. (00:14:35)
Continuity mistake: When the Doctor takes a swipe out of a jar of jam in Trish's kitchen and sticks his finger in his mouth, he only has his index finger in his mouth. The scene cuts to Rose giving him a "WTF" look, and when it cuts back to the Doctor he suddenly has two fingers in his mouth. (00:21:15)
Continuity mistake: When Rose grabs the drawing of the Doctor and the TARDIS from Chloe, the upper right corner is bent over rather sharply. In the close-up of the picture as Rose tells the Doctor she'll find a way to get him out of there, the paper is now only slightly wrinkled. (00:30:15)
Continuity mistake: When the Isolus leaves Chloe, in the shot facing Chloe where it says goodbye, Chloe's hand is raised to the wall, where the two were drawing a picture of the Earth. In the wide shot where the Isolus leaves Chloe's mouth, her arm is lowered. In the next close-up of Chloe, when she says "Mum?", her arm is raised again. (00:36:05)
Factual error: The Olympic torch relay is presented as if there is only one runner carrying the torch through the entire city of London to the Olympic stadium to light the cauldron. Furthermore, when the torchbearer collapses, the TV announcer reacts as if it is now impossible to get the torch to the stadium, just before the Doctor steps in and picks it up. Any broadcast of any Olympic opening ceremonies would show that that's not how the torch relay has ever worked.
Answer: Sec was killed and Diagorus wasn't connected to the same system as the dead human experiments. Also technically... Still a Dalek.
jakew25