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: 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: 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.