Factual error: When Hondo is introduced to the young cavalry lieutenant, Buffalo Baker remarks that it is 1870. Later, when the survivors return to the ranch, they claim to have killed Victorio; however, Victorio was actually killed in 1880 in Mexico, by Mexican troops.
Visible crew/equipment: When Hondo is being chased by the Indians after killing Lowe and gets knocked off his horse, when he jumps back onto the horse, look in front of the animal; you can see the white shirt of the man holding the horse.
Factual error: Although Hondo's story takes place in 1869/70, he packs a Colt Peacemaker, which was not manufactured until 1873.
Factual error: When Hondo first meets the woman and kid, he tells them that he is riding dispatch for General Crook. The movie takes place 1869/1870, and Crook was not promoted to General until late 1872. While it is true he received a brevet promotion to Major General in the Civil War, upon the war's end, he reverted to the permanent rank of lieutenant colonel, and was not promoted to Brigadier General until 1872.