Plot hole: SPOILER ALERT! During the final fight, Joey kills Frank and she reverts back to human form. Abigail tells her she's fine, because Frank was the one who turned her. However, when Frank kills Lambert he does not revert back to human form, even though Lambert was the one who turned him.
Suggested correction: Because it was too late for Frank, who had already turned, Joey hadn't.
If that were the case, then why would Abigail bother explaining to Joey why she reverted back to human form?
Factual error: Towards the end of the movie when Superman and Henshaw are fighting on the Watch Tower in space, Lois hits the sun shades to lower them so that direct sunlight can hit Superman and power him up. This is out in space with no atmosphere to filter the sunlight. The reason the blockers were there was for this reason, to keep the harmful unfiltered sun light from hitting people on the ship through the windows. However, she is able to stand there in the direct light after it's done and kiss and hold Superman without being hurt or burned by the intense direct unfiltered sunlight or its radiation.
Continuity mistake: When Alicia puts flowers on her mother's tomb, she casts a shadow on the gravestone in side view, but none with the camera behind her back. (00:03:05)
Continuity mistake: After the alien abduction, Emmet plans to lead a rescue mission and opens the gate asking "Who's coming with me?" During the sequence, the shadows change completely. At first he is not casting much of a shadow, then it reaches the metal doors, then it stops midway towards it. (00:20:55)
Other mistake: The opening (like most of the movie) does not make much sense, so you can pick your kind of mistake here; the special effects are cartoonishly bad throughout the big firework explosions. When John Abraham is knocked through a window by a rocket (which takes off with a 270° turn without even rising) to the face, he gets up unscathed and starts screaming for Junky and Chandu. The camera moves from them to him and he's running with the girl in the red costume in front of him (which was way behind, safely, when he crashed through the window, so already that is wrong), and then there's a wider shot. In that shot, you can tell that Adams is bumping into the same people as before and the distances between the extras are all wrong. (00:06:35)
Continuity mistake: After Wesley has intimidated the snot bully, he comes back home and finds the police. Sitting at the table, his mom holds his arm and says "Wesley, Mr. Chambers asked you a question." Mary Elizabeth Winstead has her right arm on the table, close to her body. Change of angle and she is holding the coffee mug instead. (00:45:10)
Continuity mistake: When the guy leaves the motel, he only grabs his jacket, but when he's outside, he has a helmet in his hand. (01:14:55)
Other mistake: The flight attendant pulled out a wheeled serving cart as she was talking to the other flight attendant. While shown from the chest up, it was obvious the flight attendant was moving her arms for a little while and it sounded like she was placing a few glasses on the cart then stopped, but the top of the cart was filled with glasses when the cart came back into view. Also, it was not apparent from where the flight attendant had reached to get the glasses. (00:11:25 - 00:12:12)
Revealing mistake: After most of the people trying to hang onto other people holding onto the ascending helicopter fell off, a downward view from the helicopter showed a man effortlessly hanging onto the landing skid and a woman just as effortlessly grasping his jacket's shoulder. (00:02:50)
Visible crew/equipment: As the camera moves forward in the opening shot, a clear reflection of a film light can be seen on the side of the fire engine.