Factual error: Throughout the film the British infantry are armed with carbines. These were intended for issue to cavalry and are much shorter than the infantry issue Martini-Henry rifle.
Factual error: Throughout the film the characters are often seen riding in M151 jeeps (horizontal grill slits) which were not in production until the Vietnam era. Odd because they did have a few correct era Willy's jeeps on the set, usually seen in the background.
Factual error: The group of Japanese soldiers who came to Cabanatuan following the guards desertion were not "secret police" with orders to execute the POWs as shown in the film. They were simply units who happened to temporarily halt at the camp during their retreat from the advancing Americans.
Factual error: John Wayne's squadron lands on Guadacanal as part of the "Cactus Air Force" in August 1942. However, they are flying F6F-3 Hellcats, which were not available, even to the Navy, until the middle of 1943. To top it off, they are painted in a late-war camouflage scheme with late-war markings.
Factual error: When 8-ball gets shot, in the shot which shows the platoon ducking near a wall with Cowboy, Joker and Animal Mother in the front, there are two weapon related errors. Cowboy's M-16 has a nickel (silver colored) firing assembly and Joker's M-16 has an A2 type pistol grip. The A2 types were introduced somewhere around the 80s, and nickel plated assemblies are rarely used (and were invented after Vietnam, too). The nickel assembly is visible at the beginning of the shot, and you can see the A2 grip when Joker is changing magazines (while Cowboy shouts cease fire).
Factual error: Not long into the film, D'Artagnan jumps in some hay. There's a flag of the province of Québec (Canada) visible in the background. This film is set in France at a time this flag didn't even exist.
Factual error: Col. Trautman should be wearing his rank insignia on the flash (small patch) on his beret. All officers wear their rank on their flash, enlisted men wear the unit crest. (This error was corrected in Rambo II and III.)
Factual error: The Lee Enfield rifle is chambered by singular repetitions with a bolt action. When Collins' wayward friend is shot in the water, the rifle shots are rapid semi-automatic fire.
Factual error: Reference the rural scenes. In the 40s, barley fields did not exhibit large perpendicular tracks made by crop sprayers.
Factual error: When the Marines strip off and run into the sea in the final scene, Doc takes off a pair of white socks that would be more appropriate for a final at Wimbledon. Not only are they white rather than khaki, they are virtually spotlessly clean which would be impossible after a week of fighting on the black sands of Iwo Jima.
Factual error: The worst historical distortions in this film must concern legendary "Wild Bill" Hickock. First of all he wasn't killed by a teenage boy, but one John McCall, a man in his 30's. McCall sneaked behind Hickock who was in the middle of a poker game and shot him through the head killing him instantly. Secondly this took place on August 2 1876, about five weeks AFTER the Custer's Last Stand. (01:46:30)
Factual error: During the engagement of the 20th Maine in defense of Little Round Top there is a tremendous amount of firing going on as they repel charge after charge of Confederates. Yet, there is not a single leaf, or tree branch, that falls to the ground. With that amount of lead flying around there would have been debris everywhere. There are actual Civil War accounts where whole trees were cut in half by bullet fire.
Factual error: Sarah states that Namibia is on the Ivory Coast, while in fact, it is on the Skeleton Coast in southern Africa.
Factual error: The daylight air-raid on the Norwegian Heavy Water plant in 1942 was done by Boeing B17G bombers, with the distinctive chin gun turrets. These planes did not come into service until 1944, when they were introduced to counter the head-on attacks by German fighters.
Factual error: Just as Ralph Fiennes is getting out of a car to run across the road you can see, just as he steps out, road markings that were not around in the mid forties and that weren't on the road in a shot just previous when you could see the road behind Fiennes in the car window. (01:09:05)
Factual error: The British carry WW-I, No 1 Lee-Enfields, and the Germans carry WW-II era British No. 4 Lee-Enfields.
Factual error: At approximately 27 minutes in, when they part company at the airport Douglas is wearing a Combat Infantryman Badge. The CIB was not created until Oct of '43, though the scene was taking place at the end of '41 - early '42. (00:27:05)
Factual error: This relates to the first movie with this title, the one with Jack Benny in it. About midway in the film there is a scene with Polish pilots in the RAF in a room. It cuts to a brief shot of airplanes flying which obviously purports to show the Polish pilots flying their airplanes. But, the airplanes shown are circa 1935 U. S. Army Air Corps Consolidated two place fighters, never used by the RAF and in fact totally obsolete and never used by any air force during WWII.
Factual error: When American Cosair fighter planes strafe the Japanese soldiers with their machine guns, only two columns of bullets are seen striking the ground. These planes had six machine guns; there should be six columns.
Factual error: Fairfax was not present at the trial of Charles I, although his wife Anne was, (and was forcibly removed after telling the court what she thought of them).