Revealing mistake: In the final battle, Captain Lennox is going to shoot Blackout. He gets on a motorcycle, goes really fast, and then slides off the bike and down the street. While he is sliding, he shoots Blackout. When Lennox gets to his feet, you can see his back, and his shirt is not worn away at all. It isn't even discolored.
Revealing mistake: Near the beginning Shia and Megan Fox are driving in Bumblebee, before it breaks down. There is no road shown in this entire scene, no matter which angle you see. No landscape either. This indicates the scene was probably shot on a soundstage and the car was not moving. It is also obvious there is no wind coming in through the windows.
Revealing mistake: When Ironhide shouts, "Incoming!" as Starscream fires on them, Lennox and Epps are blown backwards and slam onto the ground. The shot of them hitting the ground and the next close-up of Lennox are flipped shots. Note the reversed 'Broadway Bar' sign and Lennox's watch.