Continuity mistake: In episode one, Alex Drake logs on to the computer in Gene Hunt's office. A shot shows the date: 17-07-1981. However, on a wall calendar Alex creates at her flat, the date of July 20th 1981 is circled, with the word "ARRIVED" written in large letters. That implies she arrived in 1981 on July 20th and not the 17th. So, which is the correct date, and what happened to the 18th and 19th July 1981?
Continuity mistake: In the opening minutes of Series 2, Episode 6 (just after the recap of the previous week's episode) we see Alex Drake chasing a suspect through a crowd of "fun runners" all going for a jog. Notice that Alex is wearing a red scarf around her neck - and a narrow red belt around her waist. A few seconds later, Alex is standing alone, hallucinating, and the red belt she was wearing has disappeared.