Visible crew/equipment: Just after Lockdown stabs Optimus in the chest with his own sword, Cade runs closer and shoots at Lockdown. He then hides behind some bricks. In that shot, the bricks are a broken wall that is two separate pieces. Then it cuts to a different shot as Lockdown returns fire at Cade, and now the wall is one piece. Not only this, but some random guy suddenly appears in the shot next to the wall and right where the explosion happens where Lockdown shot the wall. He is wearing the same color clothes as the wall and only visible for a moment. There was no other guy present until that moment and he just suddenly appears behind Cade and gets hit. It's presumably a special effects member setting off the charge in the wall by the looks of it and it detonated before he got out of the shot. (02:30:55)
Visible crew/equipment: During the scene where Cade and the rest are running for their life on the roof of the huge apartment building, when the Decepticons are shooting at them, the long shot of them running shows a few crew members crouching against a wall and a camera and also another crew member crouching down in the brick doorway.
Visible crew/equipment: During the finale battle with Lockdown when Shane is driving the truck, you can see the shadow from the filming Go pro on the wheel of the truck. (02:32:35)
Visible crew/equipment: After Drift transforms into a helicopter, Optimus Prime continues driving through the desert. In the first shot after, a camera truck can be seen reflected in the chrome bumper. (00:53:15)
Visible crew/equipment: When Lucas parks his Mini Cooper next to the old theatre and steps out, you can see a crew member's reflection in the opened car door.
Visible crew/equipment: After Optimus stabs Lockdown and slices him in half with his sword, it cuts to a shot of Tessa witnessing it, and Shane getting out of the tow truck. When the camera pans towards Shane, he shouts "Yeah" and the reflection of a boom mic can be seen on the wing mirror of the tow truck just before the shot cuts. (02:33:20)
Visible crew/equipment: In the final battle scene, just after Bumblebee temporarily knocks over Lockdown, Cade shouts "Get out of here, now" and it cuts to Tessa and Shane about to get into a tow truck and Shane telling Tessa to get in. In this shot, the reflection of a crew member, most likely a cameraman can be seen briefly reflected on the door of the tow truck. (02:31:40)
Visible crew/equipment: When the red car flips through the truck during first car chase after locating Optimus at the house, the first shot doesn't show anything there, then after the car flips through truck, a camera is shown on the ground, presumably filming but looks like they never used the shot. (00:41:53)
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 ★