Plot hole: After everyone flees the family home, as Optimus is escaping he is pursued by a helicopter. He is driving down a road in a straight line. He never deviates. Yet the helicopter misses him every time, only narrowly hitting him on the side.
Continuity mistake: At the end you see Bumblebee driving in and in the far away shot you see him drift/stop in front of Cade and everyone but next shot you see him drive in again and transform.
Revealing mistake: As the flat bed trailer hits the Winnebago, the stands holding the motor home stable are visible.
Continuity mistake: As Shane is driving to escape the Black Ops cars, he drives through a chain link fence with a private property sign on it. A second later, he hits it again.
Chosen answer: The battle that lead the government to hunting all transformers was in Chicago, but the incident that took Optimus out of commission was not. He'd been on the run for however long, even changing his appearance to avoid detection, when he was ambushed. Wounded, he snuck into the theater to hide before transforming one last time into vehicle form at which point he basically passed out, lost consciousness, or whatever it is robots call it when they involuntarily shut down (stasis). His aggressive reaction upon waking is simply down to his instinctive warrior reflexes immediately kicking in. All humans are a potential threat to him now, so he reacted accordingly in an instant.
Phixius ★