Continuity mistake: When Kelly comes to make a proposition to Mulligan, the sun is on Mulligan's back. When both are in the shot from Kelly's view, both are in the sunlight. Then at the, "I need an authorisation" reverse shot, they are both in the shade, these 2 scenes are obviously shot at two very different times.
Factual error: Oddball tells Kelly their commander had been trying to get them killed ever since they landed at Omaha (beach). Oddball's tanks are part of the U.S. sixth Armored division (the Super Sixth, as the unit shoulder patch on his jacket indicates) which actually landed at Utah beach on July 18, 1944.
Revealing mistake: When Kelly is using the gold bars to persuade the others, he hands them over. There is obviously no weight as e.g. Crapgame's hand doesn't drop when taking it.
Continuity mistake: When Kelly visits Mulligan he is carrying a bottle of whiskey, he then visits crapgame who gives him a bottle of whiskey, which suggests that the scenes are the wrong way round and Kelly was originally meant to visit crapgame first.
Continuity mistake: As the squad are taking a break on top of a hill, just before the fighter-bomber attacks them, Corporal Job is distributing ammo and Jonesey can be seen walking past in the background with four boxes of K-rations. A moment later, Crapgame and Jonesey are sitting together sharing the contents of the boxes. After Crapgame goes to the jeep for some water, the shot cuts to Kelly sitting by a tree. Jonesey walks up to Kelly with a message from Big Joe - carrying four unopened K-rations boxes.
Continuity mistake: Big Joe gets out of his jeep, salutes Captain Maitland, and converses about the upcoming time off for the men. Behind Big Joe is one of his half tracks and he is on Maitland's right. The scene cuts and Maitland's "liberated" yacht is behind Big Joe and he is directly in front of Maitland.
Factual error: As Oddball and his motley crew depart with the "purchased" Tiger, Moriarity is standing up in the hatch, fiddling with his cap. Since this is the driver's position, and very cramped, either he is straddling the driver's shoulders, or driving with his feet.
Factual error: The sniper rifle used in the film is a Russian Mosin and were never used by the allies. They should have had a Springfield sniper rifle. The Americans would have had no occasion to "exchange" weapons with Russian soldiers until the end of the war, when they met on the Elbe River.
Continuity mistake: When Kelly asks Little Joe for the brandy to interrogate the German officer, he is handed a square bottle with a short neck. In the next shot, as they sit down for their "friendly drink" Kelly sets down a round bottle with a long neck.
Factual error: During the scene where Clint Eastwood is trying to convince Don Rickles to join in the heist, there is a box of Almond Joy candy bars behind Don's head. They weren't introduced until 1946.
Factual error: Almost all the German soldiers in the movie are armed with MP-40 SMGs. In fact, most German infantrymen during World War II were armed with Mauser rifles. MP-40s were only issued to squad leaders and officers.
Continuity mistake: While Big Joe is talking down to the Captain in the boat, Joe is blocking the stairs to the upper deck with his whole body. As the Captain moves up the stairs, Joe is off to the Captain's right. When the Captain emerges from the lower deck, Joe is dead center of the Captain and then moves out of the Captain's path.
Factual error: Near the end of the movie the general and the army convoy drive through the town and are stopped by all the celebrating going on. If you look at all the cheering villagers, you can see they are dressed in modern (for 1970) clothes and have hairstyles that were not around in the 1940s.
Continuity mistake: Two of the German SS Tank officers are walking together through the streets of Clairmont chatting. In the first scene with them, the officer on the left carries the rank of 'Obersturmführer,' denoted by his lapel badges, and the officer on the right has lapel badges showing him to have the rank of 'Sturmbannführer' (although both officers' shoulder badges show no correlating rank to their lapels). However, in the second scene with the same two officers still walking and chatting, the officer on the right has been demoted as he is now showing the rank of 'Untersturmführer.'
Continuity mistake: After Cowboy spots the Tiger coming down the street the scene changes to a view of the three soldiers running from away from the bank from the viewpoint of the Tiger. The Tiger's turret is facing the soldiers. In the next shot the Tiger is shown in the distance with its barrel pointing straight forward. In the next shot, the turret is facing the fleeing soldiers again.
Continuity mistake: At the end when confronting the last tank to get the bank doors open, Oddball, Big Joe, and Kelly line up in an alley as if they are directly facing the tank and start walking forward. In the next shot, which is wider and much farther away, you see that they are actually walking down a curved alley and can't see the tank until they come all the way around the corner.
Character mistake: In the scene where Crapgame is sitting in the back of the truck at the end, when the men are loading Kelly's squad's take after splitting with the Germans and Oddball, Crapgame asks Fisher to verify his calculations. There are 125 boxes of gold left valued at $8,400 per box. Fisher says that they are worth $10.5 million, and each of the twelve men in the squad will get $875,000. The actual amount (125 x 8400) is $1.05 million, making a per man take of $87,500. He's off by a factor of 10 one way or another.
Factual error: During the discussion between Crapgame and Kelly in the supply depot, just after Crapgame realises that snatching the gold from behind enemy lines would be "the perfect crime", a jet airliner can be heard flying overhead. Jet aircraft were in use by the Luftwaffe - but only on their side of the lines with the exception of a few recon and bombing missions at the front, specifically on the Remagen bridge in March of 1945,Â months after the movie's timeframe.
Factual error: The "BAR" carried and fired in the movies is actually a FN-D Model that was never issued by the US Army in WWII. It was developed post war in Europe. Also the Thompson machine guns and the 1919A4s are all firing at a accelerated rate of fire, much faster than normal. This can be attributed to the weapons being blank adapted.