Episode #2.6 - S2-E6
Factual error: The field marshal is wearing a revolver to the Derby. British soldiers are only ever armed on duty, certainly not when attending social events. He also wears his Sam Browne outside his shoulder strap instead of beneath it; no officer would do this.
Episode #2.6 - S2-E6
Factual error: Tommy's warrant is signed by the 'Minister of the Empire'. There was no such post. The Colonial Secretary dealt with the British Empire.