Revealing mistake: The "Great Train Robbery" actually took place on a two-track railway near Cheddington - the West Coast Main Line. However, the filming took place on the Great Central Railway steam line near Loughborough, which only had one track at that time. They laid a second track for the filming, but omitted to cut down a large tree at the end of the rails, which would block the path of a train. This is blindingly obvious, especially as they show this "atmosphere shot" twice. The tree is still there the second time.
Continuity mistake: In the scene in the Jaguar when they get the BBC bulletin that the farm has been found, there is a Hillman Super Minx immediately behind them. Next shot it is missing but returns later.