Factual error: Contrary to popular belief, sudden cabin depressurization in a jet plane will not cause anyone to be sucked out of the plane (unless they are sitting right up against a blown-out window), nor will it cause the aircraft to go out of control or crash.
Factual error: In the climactic charge scenes in which the three ranks of British soldiers deliver volley after volley into the Zulu masses, the soldiers closest to the camera are correctly equipped with lever action Martini-Henry rifles but those further back in the line can be seen pulling up and back on bolt action rifles, wrong for the era.
Factual error: When the "U.S." soldiers open fire on the Mexican cavalry, they employ a machine gun. The only two rapid-firing weapons in that time period were the Gatling gun, which used a magazine or drum of rounds and was fired by turning a crank, or the "Mitrailleuse" volley gun, which required at least two men to operate it, one to load the ammunition blocks, and the other to turn, once again, a crank to fire the weapon. The gun pictured has a single operator and neither a crank, nor any visible cartridge feed.
Factual error: Near the end of the movie, the prisoners are on the front of the locomotive with the German officer. The colonel is in the cab with the engineer and says "10 miles an hour, no more." Germans use metric - so the speed should've been given in kilometers per hour.