As Duke Earl is shooting at the tent, near the end of the assault you can see his other machine gun switch from his right side to his left as he is firing his weapon.
When Louie falls down the hill, he's in an open meadow with barely a tree in sight. As the men form a human chain to pull Louie out, you can notice trees in the background close to them. As the tree they're holding onto snaps, they fall and you can notice that they are in a open field again as they do so.
When Tim is hammering on the tent stake, he breaks the handle of his hammer in half, it is a clean break. When they show him looking at the handle, it is broken to a point indicating it is not the same hammer.
When Franklin is answering a call of nature in the woods, you can see the beam from his flashlight reflect off the screen from his left side.