Factual error: "Mind the gap" is written on the platform in the early scenes. The audible warning was first introduced in London in 1969, 6 years after the robbery. The written warnings were much later.
Factual error: In one of the final scenes inside the cafe of the second episode (filmed in the Olympus Cafe on New Market Street in Leeds), modern buses can be seen outside the window. These are mainly First Group Wrightbus Gemini 2 buses in First Group's latest livery since 2012. There is also the sign for "Royal Amusements" on the building opposite which didn't exist until the late 1990's at the very earliest.
Factual error: In the scenes filmed outside the picture house (filmed outside The Hyde Park Picture House in Leeds), galvanised lampposts and high pressure sodium street lanterns which were only installed since 2007. Also, a West Yorkshire branded red and cream Metro bus shelter and bus stop flag can be seen in some of the scenes.
Factual error: The robbers are using a series 3 Land Rover in 1963 which was first made in 1971. (00:46:30)