Revealing mistake: Mazhar is saved by Raghu who with his amazing strength pulls the chains tied to the tankers and breaks free. The chains supposedly pulled by the powerful trucks though are not in tension. (00:08:50)
Character mistake: Toward the end of the film, Detective Davis orders Captain McKenna to put his badge on the table. New York City police always refer to their "shields", not badges.
Continuity mistake: Right after the scene where Nels saws up his gun, he walks into a store with his arms folded. His hands are down close to his stomach. When it cuts to the next angle, they are much higher at his chest. (00:26:51)
Character mistake: Right at the beginning of the movie, introductory technobabble. "In this canister, there's a solution of protons. The canister is attached to a rotor circuit that generates the protons to the speed of light." I believe the science genius and creator of time travel mixed up the words "generate" and "accelerate" here. (00:00:50)
Continuity mistake: When Ash and friends are entering the wharf, there are two people that change between shot. There is also a person who goes from having his right hand in his lap to having it scratching his head. (00:23:06)
Plot hole: Dr. Seager told Beth that "It [Z] was all in her head" and only she could stop it. How, then, did her son Josh have the same "imaginary friend Z"? Moreover, if Beth had Z as a friend when she was eight years old, why didn't she remember him or have her memory jogged when Josh first told her about his friend Z? Also, if Beth told Z that they would be together forever (get married and have a lot of kids), why would Z need to go through Josh to get to her?
Factual error: She fires the entire magazine of a Glock into the alligator's mouth. When it is empty, rather than the slide locking back and the trigger freezing, there is an audible click every time she pulls the trigger. This could not happen.
Deliberate mistake: The prisoners in the dark dungeon would not be able to read the letter (to Miss Dudley from Jason Flemyng that the carrier pigeon had) or see such a clear reflection by pouring water on the stone floor and holding the letter (written backwards) by the water. The room was suddenly lighter when doing so, but it wasn't clear where the light was coming from. Also, sunlight coming through the small window would not beam straight down along the wall. (00:07:23)
Audio problem: The FBI agent is in pursuit of a suspect in a hospital, once he enters the stairwell he draws his Glock handgun, and a click can be heard for a safety disengaging. Glocks are striker fired, they contain no external safeties that can be manipulated that would cause a sound. A sound can also be heard after the gun is already drawn from the holster, representing a holster draw sound. (00:22:22)
Continuity mistake: Xiao Meng spent some time wrapping her father's (Professor Tao) left hand, going around his wrist/thumb and under his thumb (diagonally across his palm). When Tao was blown off the bridge and landed in the dirt, the bandage was NOT wrapped around his thumb (just around his wrist). (01:12:33 - 01:16:03)
Other mistake: Throughout this, a running gag is that Fred can't drive stick/clutch. However, in "What's New, Scooby-Doo?" Series 2, Episode 6 "A Scooby-Doo Halloween," he yells at Shaggy that he's riding the clutch too hard at the beginning of the episode. If the Mystery Machine has a clutch mechanism, he would know how to drive stick/clutch.
Continuity mistake: When Nicolas Cage aka Frank Walsh first shoots a blow dart at Kevin Durand aka Richard Loffler he hits him in the left shoulder. Ten seconds later Kevin he pulls the dart out of his right shoulder. (01:23:15)
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.
Revealing mistake: Obvious use of green screen for buildings across the street. On and off, the background fades, and buildings appear higher or lower depending on the camera's angle. At one point, the angle of walls behind Rex (Bruce Willis) is at a downward angle, and his head is almost touching the ceiling. (00:06:10 - 00:07:25)
Factual error: The movie is set in 1988, but the hurricane mentioned ("Jodie") is from 1977. (00:15:20)
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?
Continuity mistake: Before Casey enters the lunchroom and until after he sits at the table and says, "We should do push-ups", the napkins in the holder (closest to the screen) are partially leaning toward the screen. When the camera shifts to an angled view of the napkin holder, the napkins that were leaning are straight up but some of the napkins on the opposite side are leaning (away from the screen). There also appear to be about half as many napkins. (00:49:30 - 00:50:07)
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)