Factual error: French commando Philippe Kieffer is wearing the ribbon of the Military Cross throughout the film. He was actually awarded the MC in July 1944, a month after D-Day.
Continuity mistake: The book Geronimo steals from the wagon train is red. When he gives it to his wife it is black.
Continuity mistake: During the dinner scene with Bligh, Christian, Young and Fryer, watch the wedge of cheddar cheese magically change size.