Plot hole: When the fog finally hits the lighthouse and is seeping in, the generator is hardly audible vs. how loud it was when it was first started.
Plot hole: It seems highly unlikely that Lucas would be able to "mess with" Mr. Butler's application for a professorship position, or be able to accomplish what he did in such a short amount time. Off-screen, Lucas went into Mr. Butler's briefcase (foolishly left on his desk in the classroom during lunchtime) and (correctly) assumed Mr. Butler's application was on his laptop. Lucas would have to be able to figure out Mr. Butler's password (something that could take forever), find the right file on his laptop, read or scan the application to determine what he could do to mess it up, write a new answer for "qualities that make me a good teacher", and leave the classroom before anyone saw him. Lucas would also have to assume that Mr. Butler would not notice the change when he printed the application, made a photocopy, and double-checked the application before inserting it in the envelope and mailing it.
Plot hole: When the umbrella ops first get onto the train, rain has to power it up. There were plugs disconnected, and you see a hole in the fence as she shines a flashlight on it. It can't be anything infected because they didn't power down the red queen yet, and release the bioweapons. The red queen isn't physical, just controls systems. And with none of the zombies, or other infected loose yet, what else could have unplugged it? Spence was knocked out on the train, this seems to be a plot hole. (00:02:00 - 00:20:10)
Plot hole: When Peyton/Darkman is showing Bridget how the liquid skin works, he drips a small amount onto his burnt finger, and it solidifies. However, when he drops it onto his finger, it magically shapes itself into a replica of a perfect, undamaged finger. This makes no sense, as it is simply a liquid and is not being molded by any forces. Hence, it should not look like a perfect finger.
Plot hole: When Sally crushes a creature in the library with the bookcases, Not only is the crushed body still there, but also its arm on the floor, yet her father still doesn't believe her.
Plot hole: When Seth's piledriver gives out during the climactic fight, there are many vampires in the background politely keeping their distance while he tries to restart it. Similarly, they ignore him while both his hands are occupied with Sex Machine's whip, even though vampires are running around behind him to no apparent goal. (01:31:35)
Plot hole: Considering the size and power of the sharks, why didn't the female just jump the fence at the end of the film. It was only 3 or 4 feet above the water at that point. (01:30:10)
Plot hole: In the opening text scroll, it is said that the creatures live in the dark, and the name of the movie is "Alone in the Dark". But at the very end (when Edward and Aline are walking around the deserted city), the camera zooms in on the couple suddenly, implied they were attacked by one of the monsters, but in broad daylight.
Plot hole: The first time David werewolfizes, he's reading a book in the brightly lit apartment. Exterior shots of the full moon show it's nighttime out, so the lights inside the apartment must be on. But when Dr. Hirsch calls to check on him, the shot is of the phone ringing, unanswered, in the completely darkened apartment. That's considerate, David. Even as a werewolf, he must have run around turning lights off before going on his rampage.
Plot hole: When Gallagher is trying to kill the senator at the end, he is fired on by his bodyguards. Yet when they finally catch up with him, they're quite content to stand back and watch him torch the senator. One of them even lowers his gun. They couldn't have known Gallagher and the senator were aliens. (01:27:20)
Plot hole: The creature gets caught in the fishing net and (after a struggle that shook the whole boat) freed itself. The scientists, upon drawing up the net, find one of the creature's claws, and thus they now seek its source. Shortly after, while Mark is busy loading a harpoon gun, Dave is protesting, stating, "This...this thing *alive* and in it's natural habitat..." It would seem that at this point, they know the creature is *not* dead, but very much alive. They dive, they see it, Mark shoots it with a harpoon, and then upon surfacing, they argue a bit before reporting what they saw to everyone else. So why after seeing it underwater, fully knowing that "this thing (is) alive," do they act so surprised to see it, as if they didn't have a clue it could possibly still exist?
Plot hole: One alien egg is shown hanging from the wall at the start of this film, yet there's no way it can be there. The queen didn't take any with her from LV426 in 'Aliens', and if she did, she had no opportunity to place them on the Sulaco between exiting the dropship's landing gear, engaging Ripley and being killed.
Plot hole: When Freddy takes over Jesse's body at the party, there are several people watching through the patio doors when he confronts Lisa. None of these people ever make a sound, even when they see Lisa have a knife fight with a horribly disfigured man with long knives coming out of his fingers. The other party goers are completely oblivious to Freddy's presence until he comes jumping through the glass doors.
Plot hole: Mun has an eye transplant, and this gives her the ability to see the dead. However, how come she can also hear the ghosts as well?
Plot hole: After the scene of Rachel as a child, there are six days worth of events in what should be five days. Monday Lisa kills herself. Rachel works at photo hut. Tuesday Jesse and Tracy have sex, Walter is hit by car. Wednesday Rachel stands Jesse up because Mark and Eric have come to her house. Thursday Jesse and Rachel's first date - no sex. Thursday again Eric meets with the DA and Jesse and Rachel have sex. Friday is the game and party.
Plot hole: As the evolved Predator's ship takes off it leaves Casey Bracket alone in hilly forest terrain. The ship then flies a long distance before crashing and the Predator and McKenna start fighting, just for Bracket to show up and help out of nowhere. Impossible for her to cover that distance that fast in hilly forest terrain.
Plot hole: The police let Norman back to his house on the same night multiple murders happened. He is even allowed into the fruit cellar, where most of them happened. (01:38:25)