Continuity mistake: Near the end of the movie, Kate's hair is wet and she has a bloody nose. When she finds the platform again her hair is a lot dryer is and her nose is not bleeding.
Continuity mistake: The amount of dirt on George's helmet changes between shots after he gets covered in sewage.
Continuity mistake: The first train Kate boards (where Guy gets dragged off the train by a mysterious attacker) is one of the new Jubilee Line trains built in 1996. However, when Kate escapes from the train through the rear cab, the train has become a much older model built in the 1960s/70s. (00:21:00)
Continuity mistake: In the operation scene with Mandy, Creep pretends to wash his hands. He turns the tap on (left) with his hand, then off (right) again with his elbow. However, in the next shot the tap is on (left) again.