Other mistake: The registration number of the Ford Zephyr police car is RVP154G but the security etching on the window reads EKM414C.
Other mistake: In the episode where Sam has to defuse a car bomb, a small boy stares down the camera close up during the street clearance shot.
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 ★