Factual error: Toshiro Mifune's character, Kikuchiyo, travels to the bandits' camp and steals one of their two remaining fuselock muskets. Shortly afterward, the bandits fire twice at the samurai within five seconds with their last firearm. A fuselock takes as much as two minutes to reload, prime, and fire.
Factual error: The giant squid's tentacles aren't shaped like ones in the real world are.
Factual error: While travelling up the east coast from FL to ME they show a Santa Fe passenger train, which only runs out west.
Factual error: In the shot where the three officers ride the aircraft elevator from the hangar deck to the flight deck after arriving aboard the admiral's carrier, you can briefly see some of the aircraft parked on the hangar deck, and they are jet aircraft. The aircraft have pointed noses, no propellers, and the fuselage shape and markings are consistent with first generation Navy carrier jets. These types were not in service until the mid-50s (See "Bridges of Toko-Ri").
Factual error: There is a shot of a large arena where gladiatorial combats take place. Arranged around the top of the arena are a number of classical statues, one of which is Michelangelo's statue of David circa 1505 AD, 1,465 years too early!
Factual error: After the plane takes off from Hawaii, bound for San Francisco, there's a long shot of it flying among the clouds, with the left side well lit by the Sun. If the plane is flying east, in the northern hemisphere, then the Sun would be in the southern sky, illuminating the plane's other side.
Factual error: The crew gasses out the ant hill by dropping chemical grenades into the hole. But there are two reality mistakes about the grenades: 1) chemical grenades do not explode; they spray their contents into the area; and 2) considering the size of the ants, the size of their nest must be gigantic, and therefore, it would take more than a hundred grenades to flood it completely with cyanide gas.
Factual error: When David talks to Linus about the consequences of calling off his engagement with Elizabeth he says that their father would take to the bottle and smoke six coronas. Throughout the movie the old Larrabee smokes one churchill after another, but not a single corona, which is significantly shorter than a churchill. (01:02:05)
Factual error: After Gene Kelly sings "The Heather on the Hill", he sees more heather on the other side of the bridge. He starts across but Cyd Charisse freezes in horror, since to cross the bridge would break the spell over the village of Brigadoon. She then drops some of her heather in the middle of the path and runs back to the village. The camera cuts to Gene Kelly chasing after her, but the heather dropped on the path has disappeared.
Factual error: In order to make Polyphem drunk, Ulysses and his men produce 'wine' by treading on grapes. Only thing is: without fermenting the stuff for a few months, all you get is grape juice, which is not even remotely intoxicating.
Factual error: The Inspector has no authority at all to release a convicted murderer about to be executed. Even if he could, the police presence would have been greater and Margot would have been in prison clothes or at least in restraints.
Factual error: Although the movie takes place in South America, the background jungle sounds include a bird called a Laughing Kookaburra. That bird is native to Australia and New Guinea, and not native to South America.
Factual error: Jeff has been in a cast (for a broken leg) for seven weeks and has been in his apartment for most of that time. He tells his boss that he has one more week before the cast is removed and can then immediately go back on assignment as a photojournalist. By this time he should have been transferred to a walking cast and be using crutches instead of confined to a wheelchair, but he is still wearing a full leg cast that goes up to and around his waist.
Factual error: At the beginning of the movie, Forney, who is an enlisted man (a chief petty officer), replies to an officer's orders with, "very well, sir." Officers say "very well" to enlisted personnel, but for an enlisted man to say "very well" to an officer is a serious breach of naval etiquette.