Plot hole: On arrival at the Summerland castle the Polar Bear King becomes human during the midnight hour (as part of the spell) and performs his husbandly duties with his carry-on wife. Why did he not become human during the journey from Winterland to Summerland which took several days? (00:32:40)
Plot hole: During the boxing match where Eddie Murphy is wearing the special contact lenses, he sees that Owen Wilson's life is in danger. So much so, that he rushes out of the ring instead of doing his usual grand-standing. But when he shows up at the tower to rescue Owen, he has on pants and a shirt. I guess he figured Owen could hold out long enough for him to get dressed?
Plot hole: Despite their awareness of the red matter and the power of the singularity, no one on the bridge had the common sense to suggest pulling back to a safe distance. Nero had already refused their assistance so there was no need to stay so close to the singularity. And when a black hole was created inside Vulcan, an officer mentioned they had to reach minimum safe distance, so they know what they need to do, but no-one does it. (01:00:30)
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 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: 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: 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 Jack The Ripper checks his watch before confronting H.G. Wells and demanding the key, the hands point to 8:50, the ensuing chase to the museum and demise of the Ripper may have used up a half hour or so, yet the time on the wall clock indicates that it is midnight.
Plot hole: When Cateleya is in prison she changes into a black cat suit. Where has that come from? Where had she hidden that? She is wearing a very skimpy dress and would not be allowed a handbag or anything.
Plot hole: Throughout the film, anybody who speaks English uses Modern English, with either a British or French accent as appropriate. However, 1357 was solidly in the Middle English period. Although that language would not be utterly incomprehensible to modern-day travellers, neither would it be indistinguishable as it was in the film. The film specifically draws the viewer's attention to language at several points, making suspension of disbelief impossible. The French speak French, and very few of them speak English. There is a scene in which Andre is talking to Claire, and her lack of knowledge of modern idioms makes the conversation difficult; that should be true for all characters at all times. If the historical people were talking alone among themselves, I could accept that they're being "translated" for us. But they're talking directly to the modern travellers - it's too jarring.
Plot hole: When Martin decides to antagonize David by eating spinach, he eats it from his plate. When they both eat the spinach frantically, they each eat out of a large bowl. Where did the second large bowl come from, and why would there even be a second one if they only need enough for three people? (00:34:55)
Plot hole: Slater decides to render the nuke inert by punching in the wrong code three times. However, when he does this, the nuke becomes armed, and Travolta reveals that he is one step ahead by having used a special kind of circuit board to produce this result. Two questions: One, once Slater has armed one nuke, why not arm them all? You've got nothing to lose, and you can keep Travolta from getting them for whatever evil purpose he has in mind. Slater plans to send them all to the bottom of the copper mine anyway, so just arm them all. Two, Travolta later arms a nuke himself, and then smashes the keypad with his gun. Well, if you can do that, why doesn't Slater just smash all the keypads as soon as he gets the nukes? Travolta would be defeated; movie over.
Plot hole: There's no good reason for Hinx to attack Bond on the train. Blofield was expecting him to turn up at the crater, that's why he sent the car to pick them up.
Plot hole: At the end of the movie, when the water drains away, there would be no way for a) the amount of water to drain away that did and b) for the mammoths that came through to be completely dry. (01:16:20)