Other mistake: When Jakes shoots the two men on the porch of the saloon at the same time, he never aims high enough to hit either of them in the chest, as shown. At best, he would have hit them in the knee but no higher.
Other mistake: When Jake gets his horse back during the shootout at McKendrick's ranch, McKendrick's men have the horse in a stall in a barn unsaddled but still wearing a bit, bridle and reins. With a bit in its mouth a horse can't eat or drink naturally, and anyone who knew anything about horses would never stall one while it was still wearing them.
Other mistake: In the gunshot scene at the McKendrick's, a man with a sling on his arm is shot in the chest. He raises the arm, and though some blood can be seen on the sling, there is no blood or even a bullet hole on his chest. (01:48:15)