When Lucas rides out to watch Sam Buckhart talking to the Indians, he is seen with his vest on (looks like a scene from "The Gaucho.")
At the 22:20 mark, Marshal Buckhart fires 2 shots within a fraction of a second. When the scene switches to Gorman and Tub, Gorman's hand is raised in the firing position when he jerks from the bullet's impact, but Tub's hand is down in front of his thigh. Even though the shots were almost simultaneous, neither his thigh nor a man standing behind him are touched.