Other mistake: During the final shootout in the saloon, young Joey yells, "Shane, look out!" Alan Ladd whirls around and his gun goes off. But the gun isn't pointed anywhere near the bad guy who is standing on the second floor balcony. Shane more than likely shot the furnace that was off to the right. Yet, the bad guy still manages to do a face plant on the barroom floor.
Continuity mistake: When Francis Fryer throws the cowboy he loses the scarf in his hand but when the camera angle changes he has it again.
Factual error: After they bury Jack's father, the stage driver hands Jack what he refers to as a "Navy" Colt. However, in 1841, the only colt handguns were a handful of Paterson revolvers, usually carried by Texas Rangers, and in fact, the revolver handed to the boy was a cartridge weapon.