Factual error: The ribbon of Richard Burton's Distinguished Flying Cross is on upside down. The Air Force Cross following it is the right way up. The stripes on both should point the same way, as they do on the uniform of his colleague in the mess. Nobody would be allowed to get away with a mistake like this - another officer or senior NCO would soon point it out. In addition, as a long-service veteran (his colleague says he served in the Battle of Britain) he should be wearing the ribbon of the 1939-1944 Star (as it was then), which was issued to all qualified personnel from 1943.
Factual error: In the scene where Ike and the other leaders are deciding to either invade the next day or postpone the invasion, a jet plane can be heard loudly passing by through the open window. The only jet aircraft in service in the UK was the Gloster Meteor, which was developed in top secrecy; its first flight over London was on 21 July 1944, some six weeks after D Day.
Factual error: As the British prepare to march inland following the capture of Sword Beach, Lord Lovat tells piper Bill Millin to play "The Bluebells of Scotland," but Millin instead plays "The Black Bear." Additionally, he can be heard playing the same tune during the landing, but the real Bill Millin did not play that song on D-Day.
Factual error: In one scene, two British paratroopers mistakenly land in the courtyard of the chateau where one of the German generals is staying. The film depicts the two paras being overwhelmed and captured by up to a dozen heavily armed guards. This event did occur but it was actually just one of the general's middle aged staff officers with a pistol who successfully rounded up the two paratroopers.
Factual error: When John Wayne has a compound fracture diagnosis, the medic looks at John's foot with an uncovered light. Medics and soldiers were trained to use rain coats or anything available to block any light that they needed to use, to avoid drawing enemy fire. Furthermore, a compound fracture is supposed to mean that broken bone is protruding through the skin. John Wayne's skin is intact.
Factual error: The film exaggerates the carnage at Ste Mere Eglise. In this battle sequence, the U.S. paratroopers of F company (from John Wayne's battalion) of the 82nd airborne are mown down like ninepins as they parachute into the square of the village which is swarming with German troops. In reality, only about thirty troopers landed in or around the square and less than a dozen were killed or wounded, not the whole company as the film suggests.
Factual error: In the scene that introduces MG James M. Gavin, the wings on his uniform appears to be the Senior Parachutist Badge (official term for the wings), which has a star just above the parachute. The problem is that the Senior and Master rating was not approved until 1949 by the Department of Army.
Factual error: During the assault on the cliff on Point-du-Hoc, the hulking silent fellow (who is later shot in a 'duel' with a German) carries a M1 Carbine. During the climbing action, the carbine is shown without a magazine - going into battle without a loaded weapon is fatal neglect for a soldier.
Factual error: Beachmaster Colin Maud is correctly wearing the ribbons of the Distinguished Service Order (which he won in 1942) and the Distinguished Service Cross (which he won in 1940). However, he is not wearing the rosette on his DSC ribbon to indicate the bar he won less than a month after the original.
Factual error: Col Vandervoort, 2nd Batt 505 PIR 82nd Airborne Div, is shown with a 'cricket,' "1 click to be answered by 2 clicks." The code is correct but the 'cricket was only issued to members of the 101 Division. This was at the insistence of General Maxwell D.Taylor after his experiences in the airborne assault on Sicily. It should also be noted that the cricket was not shaped like a frog but was made mainly from brass by the Birmingham based THE ACME company, founded by the maker of the original London Police Force's whistle manufacturer, and they did a special run of over 7500 for the order. This makes telling original D-Day crickets from fakes easier due to die marks and press marks.