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: 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.