Factual error: The carriages on Hannay's train feature British Rail 'class' totems on the windows. These didn't appear until the 1950s, yet it is supposedly 1914.
Factual error: Towards the end of the film Hannay and Chief Superintendent Lomas are interviewing two senior naval officers about the fake Sir Walter Bullivant's activities. One of the officers is wearing medal ribbons including the British War Medal and the Victory Medal. These were instituted in 1919 for serving in the Great War, but the film ends in May 1914, about 3 months before the war had even begun.
