Plot hole: When the Grundel explodes near the end, Rowan looks out the window to see Uber Jason floating towards the rescue shuttle, only to be grabbed by Brodski who happens to fly sideways at a high rate of speed. Now provided it's feasible that Uber Jason can survive an immense explosion, how Brodski not only survived the explosion but managed to wind up away from the spaceship and far enough off to the right so as to catch Jason in mid-space is beyond me. (01:22:15)
Plot hole: When Tim Robbins is floating away in space his wife could have easily saved him. She could go out a little further, use the grappler to catch her husband, then use the fuel she has remaining to halt their acceleration towards the planet and return them partway to the necessary orbital altitude/velocity to rendezvous with the resupply module. Then, Gary Sinise could come out partway to them using his thrusters, Connie could shoot the grappler out to him, and he could reel both Connie and Tim Robbins back in to the resupply module.
Plot hole: If Old Biff changed his past and went back to 2015, he goes back to HIS future, not the bad future, but Doc later tells Marty that if he were to go to the future to stop Biff from taking the almanac, he'd go to the bad future, so Old Biff technically shouldn't have been able to return to "his" future at all.
Plot hole: When Magneto lands the bridge between San Francisco and Alcatraz, only the ends of the bridge are on land, with the rest still suspended in the air despite having nothing to keep it there. Magneto could arguably be using his powers to keep it supported, but at the moment he loses his powers it still does not collapse at the center.
Plot hole: Stuart establishes that there is only one of you and that when you travel through time you can repeat things, but it will be you and not your double that does it. But, at the end, when the Duke is going up the stairs and the uncle says "Where have you been...", the Duke is wearing the same clothes as the first time. Yet we see that he goes directly from the time portal to his house in the ballroom raiment of the later scene. Where did the old clothes come from?
Plot hole: Kazam is supposed to be a math genius, something that the plot hinges on, but he makes several mistakes when calculating the number of prime factors to find out whether a room is trapped or not. He says that 462 has three prime factors, when it has four, that 206 has four when it only has two and that 563 has two and 911 has three when both are actually prime numbers.
Plot hole: Whatever happened to the one legged henchman? He was one of the villain's lead goons in the first half of the film, but he simply disappears after the scene in Chinatown. The previous correction that "Peyton didn't have time to track him down" is complete nonsense. He literally vanishes from the film. (Due to a deleted scene, but that's no excuse either way.) There's absolutely no reason he still wouldn't be in Durant's gang and in the remainder of the film.
Plot hole: In the last car-chasing scene, the timekeeper had switched his car to chase them, then how could Justin Timberlake get the timekeeper's salary (a day's time) from a car that the timekeeper picked up from the streets?
Plot hole: On the doors inside the white dome, and on the elevator door, it is marked "Vapor Lock." This is impossible due to the mine shaft opening. It can't be vapor locked when there's an opening. (00:35:00)
Plot hole: Even if someone would make all nuclear powers launch their nuclear missiles and then destroy them you still wouldn't have a nuclear weapons free world as most of those nations have plenty of nuclear weapons in reserve. A lot would be even be armed and ready to go for a possible second strike. (01:24:10)
Plot hole: When you see the shot of New York, just before the scene where the apartment lights go out, there are no lights on in the buildings, or car lights in the street, although it is dark. The lights should still be on as there has not been a power outage. (01:28:00)
Plot hole: In the course of the story it's said that at the time the black hole went out of control, it had a mass of "half a mountaintop of granite." But in a flashback scene Dr. Krone is shown growing the mass of the hole by feeding it large numbers of lead bricks in the laboratory. It's a little hard to believe his lab could store, or even afford, enough lead bricks to equal that much mass.
Plot hole: A nuclear armed stealth fighter is accidentally sent back in time to 1940's Nazi Germany. After the Nazis capture it, two days later they drop a nuclear bomb on the United States. There are several basic problems here. Firstly, if the Nazis captured advanced technology, wouldn't they spend more time taking the plane apart and interrogating the captured pilot? How on earth did they manage to train a pilot to fly the stealth in such a short length of time? And how did the stealth fighter manage to reach the U.S. from Germany when in-flight refuelling was unknown then?
Plot hole: When Ripley goes to access the computer Mother, the entry door opens and closes with a hissing noise, a couple of minutes later you see Ash next to Ripley with a smile on his face. How did Ash manage to open the same door without it making the hissing sound? Ash could not have been in the room before Ripley came in - once Ripley has sat down at the console, it rotates on a 90 degree angle, this would have made it impossible for Ash to be hiding behind a desk or a computer console without being seen by Ripley. There are many doors on the ship that make the same hissing sound when the doors open, an obvious example is the infirmary door. And Ash couldn't have disabled the pneumatics of the door, because when Ripley exits the room, the hissing noise is heard again. (01:18:40 - 01:20:00)