Revealing mistake: When Bumblebee drives up the KSI building, he swerves the car around to face the building and let Tessa and Shane out. The tyre marks are visible on the ground before he swerves the car, most likely from a previous take. (01:12:10)
Revealing mistake: When Galvatron is firing rockets on the Autobots, a flatbed truck swerves into the back of an RV causing it to flip over and explode. There is no driver in the RV. (01:17:40)
Revealing mistake: When Tessa and Shane are trying to free Optimus from being impaled to the wall after he is stabbed with his sword, there is a shot of Tessa running towards Optimus after she grabs the hook belonging to the tow truck. In the background of the shot, the Willis Tower, also known as the Sears Tower, can be seen in the far background. The buildings surrounding the tower can also be seen as well. The Willis Tower is located in Chicago, but the scene is set in Hong Kong. The scene was likely filmed in Chicago. (02:32:40)
Revealing mistake: When Bumblebee is transporting Joshua, his face is cut from another shot and placed on the one of Bee driving. This is obvious by the incorrect lighting on his face and lack of reaction to his surroundings.
Revealing mistake: As the flat bed trailer hits the Winnebago, the stands holding the motor home stable are visible.
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 ★