Other mistake: During "Cool," there's a shot where they're doing a sort of knee turn, and you can see Tucker Smith in the background spinning too many times (you can see him start to stick out his arms to stop himself). (01:58:20)
Other mistake: When the girls leave camp, if you look closely it is obvious that one of the girls (the one in the distance) is a double who does not look like Susan / Sharon at all.
Other mistake: When they're roping the mustangs, the "stallion" doesn't have the genitals of a stallion.
Other mistake: After the Cid dies and is propped up on his horse to try to fool the enemy into thinking that he still lives, he leads his army out of the fortress and attacks the offenders. Just after he comes out of the gates the horse stops and there is a shot of the Cid on his horse being almost silhouetted against the sun. If you watch carefully you will see Charlton Hestons' head move slightly and look towards the direction of the enemy.Even though the horse turns slightly under him the Cid's' head keeps looking in their direction. Obviously this would be impossible if he was dead, and even more so when you remember that his body was supposed to have been tied tightly to a support so that he would sit upright when on top of the horse.
Other mistake: When Fats makes the 7 ball after Eddie's safe play, you see the cue ball flying into the pocket before the camera changes shots.
Other mistake: When Regret, Jake, Pilar and her father are escaping from the Comanchero village, there's a close up of Jake (Wayne) in the back of the wagon shooting a rifle. The scene shows him shooting left-handed. It's a reverse print. Look at his "right" hand in the scene. He has a ring on his "right" hand ring finger. A few moments later, setting the wagon canvas afire trailing out the back of the wagon and shooting right handed, the ring is on his left hand as it is in the rest of the movie.