Revealing mistake: In the scene out West with the buffalo, notice the car driving in the distant background.
Revealing mistake: In the scene right after they leave Scar's wigwam, when Ethan and Martin are speaking to each other around their camp you are able to see a small brown dot right above the sandy hills. This dot is the character Debbie's head while she is waiting for her cue before she runs in to the scene.
Revealing mistake: When Jordan and Jett go into the liquor storage room for Jordan to teach Jett a lesson for beating up Jordie, Jordan instead throws a large wine basket at the shelves of wine/alcohol. The shelves start to fall before the basket even hits them. (02:44:55)