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: When Sam is talking to Mikaela's boyfriend, you can see the camera and crew reflected in the Hummers mirrors.
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.
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.
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 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.
Visible crew/equipment: When Banachek and Simmons are talking to Sam at the entrance of the Hoover Dam, you can see the white lighting panels reflected in their sunglasses.
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.
Continuity mistake: At Hoover Dam, when the soldiers salute Keller the clock reads 10:00, then as Keller, the soldiers, Maggie and Glen walk away in the background, when Simmons tells Sam that they got off to a bad start the clock reads 11:35, and next shot when Banacheck interrupts it reads 11:43. Also when Simmons talks to Mikaela and Sam the word "Nevada" is gone and it only reads "Time" under the clock. Then when Banacheck says, "Come with me, we'll talk about your car," the word "Nevada" is back under the clock.
Continuity mistake: When Prime lifts Mikaela up to Sam's bathroom window, there are two baseballs in acrylic display cases and another object (looks like a vintage camera) on the windowsill (beside the tub). Then when Sam runs to that window and sees the Autobots parked as if it were a "truckstop", all those items disappear and are replaced by two small overturned flowers pots.
Continuity mistake: While standing in front of a frozen Megatron, after Banacheck explains that Sam's great-great-grandfather made one of the greatest discoveries, Sam and Mikaela are shoulder to shoulder, but in the next back shot they are 4-5 feet apart. They're beside each other again in following shots.