Factual error: When Resiman interviews him in prison, Franko is chewing gum. (In several shots you see it is chewing gum and not tobacco). First, during heavy rationing in the UK in World War 2 chewing gum was a rare and expensive treat. A military prisoner would not be able to obtain it for love or money. Secondly, US military prisoners were never, ever allowed chewing gum - it can be (and has been) used to jam locks.
Factual error: The film opens with a US soldier being hanged, the lever is operated by a US Noncom. Wrong. The US forces were allowed to hang their own on British soil, but only if a British executioner was used. The executioner would have been our own Mr Pierrepoint.