Continuity mistake: In the scene where Sam has just been clipped by a car in the first episode, Sam is rolling off the car with the car rear in this shot, however when we cut to an overhead shot of the car, Sam is seen to be rolling off the car AGAIN before he hits the floor.
Factual error: Gay pride flags are visible in a window. The 6 color flags shown were introduced in 1979 (though an 8 color flag preceded it in 1978). (00:30:44)
Factual error: The reflection of a blue DAF XF lorry can be seen in a window. These lorries were not made until many years later. (00:31:51)
Character mistake: Sam encounters Marc Bolan in the club and warns him to "drive carefully", aware of Bolan's future death in a 1977 car accident. However, Bolan never learned to drive and he was actually a passenger in the fatal accident. (00:07:55)
Continuity mistake: When Sam and Gene enter the pub with the T.V., they both stand at the bar with Gene leaning one hand against the bar. In the next shot Gene is leaning on it with both hands. When the shot cuts again he is back in his original position with one hand on the bar.
Continuity mistake: Sam and Gene are discussing how to deal with Stephen Warren and having a drink. Sam holds the bottle of scotch with the label facing away from him. It immediately does a 180 degrees turn as he takes a slug from it.
Factual error: At the end of the episode Sam walks down an alley looking for the son of the murder victim. In the background small split-system air-con units are visible on the outside of some buildings. These were not available at this time. (00:48:30)
Revealing mistake: When the Capri crashes into the goal net & they go to arrest the suspect you can see sky satellite dishes on the houses in front of them. Satellite TV didn't start in the UK until the 80s.
Factual error: The supposed keys used to kill Colin Clay were a modern type not yet produced at that time.
Factual error: There is a phone ringing in the police office, but it is using the American style ringing tone - with a single, repeated, long ring - instead of the British ring tone - two short rings repeated. (00:00:24 - 00:01:17)
Factual error: Sam's watch (which we see when he checks it just after the escape attempt) is a quartz movement "analog" with a little window at the bottom where an LCD (Liquid Crystal Display) display shows the date. LCD didn't appear on watches or calculators for another five or six years.(Although in 1973, there were Digital Watches with LED (Light Emitting Diode) displays. (You can see Roger Moore as James Bond wearing one in "Live and Let Die"(1973)).
Continuity mistake: When Gene and Sam are having a discussion in the gents, his tie goes from being lopsided to straight, despite his hands never leaving his pockets.
Chosen answer: Sam is using the modern wording of the right-to-silence caution prescribed by legislation such as the Criminal Justice and Public Order Act 1994. In the 1970s, the wording would have been different, if it was used at all.
Sierra1 ★