Corrected entry: The doctor in the ambulance tells Jim Brown, "You're wearing Air Force insignia." The name Air Force was not used until 1947, just after WWII. It was called (Army) Air Corps during WWII.
Correction: It isn't "air force" it is "Red Force", as in the arm bands they were wearing which showed which side of the exercise they were on.
Corrected entry: After Lee Marvin turns the hookers loose on the prisoners, the Army psychiatrist quips "Do you think those guys realize tomorrow is Mother's Day?" Subsequently, when Marvin is being berated by Robert Webber for holding the drunken party in which the hookers participated, Webber notes the date of the party was April 14 and 15. Mother's Day is celebrated in May.
Correction: Copied, edited and pasted from IMDb.
Corrected entry: Towards the end of the movie where American soldiers were trying to remove the tops of the air vents, a German sniper has his cross-hairs on a soldier's forehead. When the sniper shoots, the next view is of the American putting his hands up to his face. The American was shot in the forehead which would negate any conscious after the fact movements on his part.
Correction: Not necessarily so. There have been many documented cases of people being shot in all parts of the head (some more than once) who retain consciousness and control over their actions/movements.
Corrected entry: Prior to the attack on the Chateau, one of the team climbs a telegraph pole to cut the phone lines. To support himself he uses a brown and yellow webbing belt of the type introduced to British telephone engineers in about 1968. During WW2 a leather belt would certainly have been used.
Correction: I just watched the movie and played this scene several times, including a single frame advance passage. I can assure you that the belt is not "a brown and yellow webbing belt." it is plain, light brown leather.
Corrected entry: As the convicts are building their training camp, Posy is shown with blueprints and a clipboard on which he is writing something. Later, when Posy comes out from talking with the psychologist, it is firmly established that Posy is illiterate: "The captain thinks he can teach me letters." How can he be reading blueprints and lists?
Correction: Being illiterate wouldn't keep you from reading a diagram or drawing like blueprints. Posy could have been putting markings on the blueprints, not actually writing words.
Corrected entry: Bizarrely, this film is partially based upon a real incident - the ending of which is somewhat different to that in this film. Twelve US soldiers on death row or serving long prison terms were selected to undertake a highly dangerous mission behind enemy lines in France in 1944. One of the US Army officers responsible for them was Ernest Hemingway, another was - of all people. - Russ "Supervixens" Meyer. All twelve were intensively trained and then transferred to a transit camp near Caen to be prepared for their final mission. As soon as they landed on French soil, all twelve deserted.
Correction: During WW2, Hemingway was a war correspondent for Collier's magazine, while Meyer was a combat cameraman. Neither would have been given any degree of responsibility for a special mission. However, despite rumours to the contrary, no such mission ever took place. It's believed that the Dirty Dozen was inspired by a group of elite commandoes from the 101st Airborne Division, who were nicknamed the Filthy Thirteen and who were trained to demolish targets behind enemy lines. However, while the group had a reputation for hard drinking and fighting, and some did possess criminal records, unlike their fictional counterparts, none of them were convicts.
Corrected entry: When the Major and Wadislav walk up the stairs in the German mansion they are met by a pair of German officers who say something to them. Wadislav then tells the Major that he couldn't understand a word they said. What they actually said was 'Nice weather, wouldn't you agree?' Wouldn't you think that a man who speaks German well enough to convince the guards in a German HQ would understand such a simple phrase?
Correction: Not necessarily. He probably studied common phrases he would expect the soldiers to use (i.e. "Yes sir", "Where are your papers?", etc.) so he could be effective during the mission. He probably wouldn't have studied idle chit chat.
Corrected entry: We never actually see Posey (Clint Walker) die on film. We know where he is during the mission and we only saw his partner Bravos get shot but not Posey. I always have this funny feeling that he may have survived and the surviving members (Lee Marvin, Charles Bronson, and Richard Jaeckel) of the Dozen forgot about him.
Correction: They assumed he was dead after the huge, bloody battle they had just gone through. Either that or he is MIA - Missing In Action. Not a mistake either way.
Corrected entry: When Donald Sutherland is pretending to be an incognito General inspecting the troops (as the camera pans down the lines of solders to inspect) a helicopter can be seen clearly in the distance over the soldier's heads. While helicopters were air tested during WWII, it is highly unlikely to see one in service.
Correction: There is no helicopter in the scene at the Air Force base; it's a light plane. It is steeply banking so the wings aren't clearly visible, and the shape of the fuselage makes it look like a helicopter. It's too ar away to tell what type it is but it could easily be a WW2 vintage.