When Bacchus is in the pub he is attacked and headbutted in the face the perpetrators would've been done for assaulting a police officer.
In the final scene the murderer is executed. Murder by stabbing became non-capital in Britain in 1957, several years before the series is set.
Gently and others are rushing to a holiday camp at Cullercoats, a coastal settlement in the former county of Northumberland, now Tyne and Wear. At one point the cars come to a road junction where there are two road signs. One sign points to Cullercoats, it has the road number A431. The actual route of the A431 runs from Bristol to Bath.
Taylor has three chevron stripes on the sleeves of his uniform tunic, which denote the rank of Police Sergeant. His colleague John Bacchus is a Detective Sergeant. Despite both officers being of equal rank, Taylor often calls Bacchus, Sir.