When Jack Crabb is shown drunk during a heavy rainstorm shots alternate back and forth from being on an overcast day to being ones in bright sunshine.
When Shadow That Comes In Sight rescues young Jack and Caroline after their parents were killed, you can see Caroline put her foot up to a stirrup as she mounts the horse behind Shadow. When she dismounts it appears that Shadow, like most other Cheyennes, rides bareback.
During the Civil War, George Armstrong Custer was brevetted at various times to the ranks of Major General and Brigadier General. However, by the time of the Battle of Little Big Horn (well after the end of the Civil War), Custer's rank was reduced to Lt. Colonel. In the film, his uniform does not reflect this and the men incorrectly refer to him as "General Custer" prior to and during the battle.
When Jack and Olga are being photographed in front of their store the photographer removes the lens cap to expose the film and we see the image being taken reversed on camera glass. In reality the film holder would have blocked any view during the exposure.
Custer split his forces into three battalions, one that he commanded, one that was led by Major Marcus Reno, and the last one, under the command of Captain Frederick Benteen. Both Reno and Benteen's Battalions would survive the battle, only Custer and 210 men were completely wiped out, with there being 268 total dead.
George Armstrong Custer is shown wearing the two star rank insignia of a Major General, which was his brevet rank in the Civil War. But as a cavalry commander in the Indian Wars, he had reverted to his Regular Army rank of Lieutenant Colonel, and should been depicted wearing the silver oak leaves of that rank.
Many inaccuracies regarding the Battle of Little Big Horn are copied from They Died with Their Boots On (1941): see goofs for that movie.
The wires forcing a horse to fall are visible in the final battle scene, just before Custer exclaims "Fools! They're shooting their own horses!"
During the credits at the beginning of the movie, young Jack comes out of hiding and looks at a man's body, with an arrow sticking up out of it. The top of the arrow moves slowly as the "dead" man breathes.
When Jack meets Mr. Merriweather late in the movie, Mr. Merriweather has lost his right leg. As he is limping away after their encounter, the outline of his right foot is visible through the back of his duster.
Following the movie time line, Jack Crabbe should have been rescued from the Indians around 1865. When he enters his gunfighter period around 1866, Jack is carrying two 1873 Colt Peacemakers while Hickok's pistol is an 1882 Colt.
When Jack first sees Mr. Merriweather, Merriweather is using a bass drum pedal. The first bass drum pedal was not patented until 1909 by William F. Ludwig.
The red and white guidons were not in use until 1885, 9 years after the film's setting.
The use of the Springfield Trapdoor Rifle at the Battle of the Washita in 1868 is an anachronism because that weapon system would not have been developed until 1873, even though early versions of the weapon were in use, the 7th Cavalry were using 7-shot Spencer Carbines that were developed during the American Civil War, and they would not get the 1873 Springfield Carbines until 1875.
Winchester 1892 rifles are used.