When Mark Sanger is driving the wagon along the road, a goon shoots a bullet at the rear right tyre which misses it, in the next shot, that tyre is flat.
In the scene where Mark Sanger goes to talk to the guys in the repair truck, he leaves the passenger door of the wagon open. He then tells them he's going to get a cup of coffee and before he leaves the wagon, he forgets to close the door.