Continuity mistake: After the bird of prey first fires on Enterprise, Kirk is thrown right out of his chair to his left and lands on the floor. The camera pans around the bridge briefly, seeing the rest of the crew staggering and holding onto things. In the very next shot Kirk is back in his chair shouting "back off, back off" and the crew back in their positions as if nothing has happened.
Continuity mistake: When Grumpy jumps the chasm to chase Dr. Marshall, there's a large green bulbous plant that moves from the side Grumpy jumped from to the one he lands on. It wasn't there before.
Continuity mistake: When Ken Wheatley is pointing his tranquilizer gun at Zia after he shot Owen, he puts the gun in his left hand and uses his right hand to wave his men down, but mid wave, the camera cuts to a different angle and he is waving with his left hand while holding the gun in his right hand. (00:30:00)
Continuity mistake: During Sandman's attempted heist of the armored truck, he punches Spider-Man through the side of the truck, and the damage to the armored wall significantly changes in the following shots.
Continuity mistake: When the T-rex is in San Diego and is about to smash the bus, the driver tells everyone to get to the side. There is a guy in a seat right behind the driver, but when we go outside the bus just before the T-rex crushes it, that guy is no longer there. (01:52:05)
Continuity mistake: At the end, during the fighting in the Cathedral, the last woman left is getting first cut by Steven Seagal at the right breast. A moment later, her cut is on her left side. The next moment it is on the right side again.
Continuity mistake: After Peter gets the text from Happy about meeting at the bathroom, Michelle asks, "What are you hiding, Peter?" and just as she says, "I'm just kidding I don't care," Peter's holding his cell phone up in his left hand, but next shot he's holding the cell phone up in his right hand.
Continuity mistake: When Peter and MJ hug on Tower Bridge he gets some blood from his face onto the left shoulder of her jacket. From other angles there's no blood.
Continuity mistake: When the men first enter the spaceship, one of the windows shows an afternoon sky and the one next to it shows a nighttime sky. (01:11:20)
Continuity mistake: The birth of the Predalien in this movie is completely different than it was in the first AVP. The lights on the table are different and the Predalien bursts out differently than in the first film. (00:01:30)
Continuity mistake: When the members of the League are attacked at Dorian's home, the fight is accompanied throughout by a blizzard of paper falling from a height, yet hardly any of the books have been disturbed on their shelves. (00:28:40)
Continuity mistake: When Simon Phoenix gets out of the sewer system (after gunning it out with the rebels and John Spartan) his left eye has the brown contact and his right eye has the blue one after going the entire movie with those contacts in the opposite eyes. (01:30:25)
Continuity mistake: After Sharpe and Stamper have the argument on the asteroid, Truman says they need the radio back up. When he says this, you see the countdown clock for the asteroid which is at five hours and 12 minutes. A bit later in the film, after the nuke was shut down by a technician at NASA, one of the Air Force Sergeants takes the terminal. In the background, you can see the clock again but the time on it is at six hours and 49 minutes. (01:37:00 - 01:42:50)
Continuity mistake: When Marlon stocks the vending machine, the camera (inside the back of the machine) shows him stocking the 1st row with brown-wrapper candy bars. He starts stocking the 2nd row with yellow-wrapper bars; Truman interrupts him for a minute (during which Marlon doesn't touch the bars at all). When Marlon continues, the yellow bars have changed to something darker (it's not just a different camera view; even barcodes are different). After another brief interruption, Marlon continues again, and the yellow bars are back. (00:35:00)
Continuity mistake: As Brian lands the plane down to Bangor, his headset is on in a frontal shot, but in a reverse shot it isn't. (00:47:05)
Continuity mistake: The Bird of Prey is the one captured by Kirk's crew in ST III. That ship's bridge showed Klingon Cmdr Kruge in his elevated command chair with his helmsmen arrayed circularly below him, and nothing else. ST IV has this same ship; however, the bridge now resembles The Enterprise layout with Kirk's command chair behind Sulu and Chekov at their rectangular helm, with Spock, Scotty, and Uhura at their usual positions.
Suggested correction: According to the captain's log at the beginning, they have been on Vulcan for 3 months. As they prepare to depart, we see several Vulcan technicians moving equipment in and around the ship. It's quite conceivable that the bridge was reconfigured according to the crew's specifications to facilitate their use of the ship. This may seem a bit excessive, as the remodel includes the door onto the bridge, and the frame of the door, and possibly most of the rest of the ship. But it's not outside the realm of possibility. The real mistake, though, is why they would go to the effort of installing new workstations on the Klingon bridge and marking them with Klingon labels, instead of standard Federation text. Interestingly, though, the "Starfleet" style bridge layout of the Klingon ship is being used by the Klingons on the Bird of Prey in Star Trek V.
Continuity mistake: In the first encounter with Brigham, Cage has one button on his jacket undone during one shot, and in the next shot it is buttoned up.
Continuity mistake: In a scene early on where Mike is behind the video shop counter and Jerry is in front of it, the positions of the videos on the shelves behind Jerry alter from shot to shot.
Continuity mistake: The photo of Cleric Partridge with Mary O'Brien is crumpled and folded when we first see it in the morgue and when Cleric Preston shows it to O'Brien. However, when Preston is sitting at his desk and looking at the photo by himself, closeups of the photo show it as smooth without the signs of wear and tear seen previously. (01:01:25 - 01:03:20)
Continuity mistake: When Jack is briefing the President, he draws a line on a map of the U.S. and tells the President to have everybody south of that line evacuated. The shape of the line changes three times between shots. (01:04:20)