At about the 24 minute mark when Dave is fighting with Nichols, Dave gets punched into a chair and falls back over. When he lands, Richard Martin (Chito), who is already on the floor, inadvertently gets kicked in the head.
Really stupid to disarm the bad guys, then ride off leaving their guns on the floor, rather than taking them or tossing them where the crooks won't find them so easily. Even dumber to do it a second time when they find them in town.