Erreurs factuelles: One of the admirals says that D-Day must be June 5 or 6 because there would be a neap tide, as required. In fact the date was selected for the opposite reason: there would be a spring tide, as required.
Anachronismes: Charlie refers to war widows leading the Memorial Day parade. But the day was originally called Decoration Day, and wasn't changed to Memorial Day until after World War II was over.
Anachronismes: The airplane that takes the Admiral back home bears a USAF roundel (i.e., red strip inside the "wings") three years before there was a "USAF".
Continuité: In one shot of Charlie's hotel room door, the exterior of the door is white, in another the exterior of the door is wood grain.
Erreurs factuelles: The uniform of the American General Hallerton is incorrect. He is wearing a black tie (phased out in favor of the 'pink' tie and shirt in 1942); also his shoulder sleeve insignia denoting European Theater is sewn on upside down.