Continuity mistake: When Jack is alone in the desert and the girl's Jeep stops nearby, he is positioned towards the right-front corner of it. But when he approaches it, he walks into the scene from the left-front corner of it. There's no reason he'd walk way around the area - he is suffering from the heat and would walk as little as possible, in a straight line to it.
Continuity mistake: The cop (Marty) enters the diner and shoots three patrons before killing himself. Moments later, the security tape that the Army watches, has the timing and positions of the characters a little different. Clearly, they had to re-shoot the scene from the different angle.
Continuity mistake: The Army Humvee arrives in Piedmont and finds the townsfolk all dead. The timecode on the truck's video recording is 22:13 hours. When the team gathers to learn of the situation, they are shown this video. The General then presents a video he says is 2 hrs later, the view from the drone with infrared film. The time code on this, is 3:15. Both were shot in the same place, and both would be local time, so the time is wrong. More to the point, the original drone footage did not have any timecode on it.