Continuity mistake: Odd how Mikaela is not wearing her stud earrings when Sam leaves her to go to Bumblebee and she spots the tow truck across the street, and also when she arrives in the tow truck and says, "Sam, help me with this." Yet, she is wearing them between those shots, when she breaks into the tow truck and hotwires it, and in the prior and following shots.
Visible crew/equipment: At Hoover Dam, after the salute, when Defense Secretary Keller speaks with Lennox and Epps, the reflection of the white reflector screen is visible on Keller's glasses. What's more, the boom mic's reflection is actually visible within the reflector screen's reflection. Two for the price of one.
Continuity mistake: When Sam and his parents are being arrested by the Sector 7 officers, inside the house Sam is wearing a blue Strokes t-shirt over a long sleeved shirt. When the shot changes and Sam and his parents are being led in hand cuffs to the police cars, a brown sweatshirt is tucked between Sam's left arm and his back due to the handcuffs. In the next shot, Sam is wearing the brown sweatshirt as he says a line of dialogue. The camera cuts to Agent Simmons of Sector 7, then goes back to Sam, who is now wearing the Strokes shirt and the brown sweatshirt is draped over his left shoulder.
Continuity mistake: During the final battle, Sam rolls on the pavement and reverses direction as a jet-bot lands and transforms. The next wide shot shows Sam scurrying alongside the passenger-side fender of a black Mercedes sedan as another black car is tumbling over the Mercedes' hood, its doors wide open. This same moment repeats in the next shot, from another angle, but suddenly Sam isn't at the fender of the Mercedes- he has vanished. The angle changes again and the same moment repeats a 3rd time, and Sam is still missing. Then, a closeup shot is looking up past Sam as mayhem rages above, and the black Mercedes he huddles against is suddenly a red car.
Continuity mistake: In this movie, we see a close up shot of Mikaela's hands in three separate scenes. The first is a shot from behind Mikaela and Sam where they grasp hands and the camera closes in on that. You see Mikaela's short nails, with chipped red polish. The second time we see her hands is a shot where she covers her open mouth with both of her hands in shock. Her nails are unpolished. Finally, the third time is during the ending sequence where both she and Sam have been thrown to the ground near each other. Mikaela stretches her hand toward him, they touch fingertips, and the red nail polish is back.
Visible crew/equipment: During the attack on Hoover Dam, after Simmons rejects Sam's request to be brought to Bumblebee, when Simmons tells Lennox to drop his weapon, in the next overhead wideshot the grey tape marker between Lennox's and Simmons's feet is visible, as well as the tape marker at Secretary Keller's feet.
Other mistake: During the chase scene on the highway, when Sam says, "It's the same cop," they pan to a wide shot to show the whole freeway with the cars on it. All of the vehicles are on the wrong side of the freeway. When looking out of the back of his car, you can see the fronts of all of the cars coming towards the camera, and you can see the text on the signs facing the camera as well. You can also see crowds on the flyover, watching the filming.
Continuity mistake: After class when Sam rushes to his father, who is waiting in his car, and tells him that he got an A-, the license plate is affixed to the front bumper. At the start of the next shot, the front license plate is gone, but it then reappears when they arrive at Bobby B's.
Continuity mistake: During Sam's family genealogy report, when he holds up Captain Witwicky's glasses to show the class, there are cracks in certain areas of both lenses. Those cracks actually change position and characteristics when we see the glasses elsewhere in the film, such as on eBay and when Prime explains their importance to Sam and Mikaela when they first meet.
Continuity mistake: In the scene in the interrogation room with the two programmers there is a big plate of doughnuts which the hacker eats very quickly. But take a look at the plate between shots when he's talking and you'll see that the amount of doughnut left on the plate varies greatly: Sometimes there's one whole doughnut left, other times, in the same conversation, there's only crumbs.