Gently Between the Lines - S6-E1
Factual error: Just before the end of the episode, the custody Sgt is arrested in connection with the death of the prisoner, and the modern day caution is used, which was not introduced until the '90's.
Inspector George Gently (2007)
1 mistake in Gently Between the Lines
Starring: Lee Ingleby, Martin Shaw, Simon Hubbard
John Bacchus: You're under arrest.
George Gently: He's under arrest, when I say he is.