Plot hole: The only reason the terrorists' plot can work is that the airports around Dulles are all closed to landings because of the violent snowstorm. If there were no storm, the pilots of the airliners in the holding pattern would simply divert to nearby airports when they started running low on fuel. If they were able to do that, the whole plot would simply fall apart. How were the terrorists able to count on the storm happening on the very day General Esperanza's flight was due to land? They didn't have any influence over the date of his flight. How did they know the storm would be so bad that all airports would be closed - except Dulles? I don't think they had any way of predicting the weather quite that accurately, and If the storm hadn't hit or had been even slightly less severe the pilots of the stranded airliners could easily have diverted to any one of half a dozen alternate landing sites, including a nearby Air Force base. They could do this without consulting or even contacting air traffic control. The whole plot falls apart from there - no hostages, no leverage, and who cares what happens to the people on Esperanza's plane? They'd have it shot down as soon as they knew Esperanza had killed the pilot and taken over the flight.
Plot hole: At the end of the film, we see Edward carving ice sculptures in his mansion. How did he get the ice up there? First of all, it takes place in a warm climate and I didn't see a freezer up there in the castle. He couldn't have gotten ice from town because firstly he had scissors for hands and couldn't have gripped the ice. And, even if by some miracle he could, he wouldn't be able to buy any from town because everyone in town but Kim was convinced that Edward was dead, she told everyone that they killed each other. And Kim didn't bring it to him because she told her granddaughter in the end that she never saw him again after that night. So where did he get that ice?
Plot hole: In the scene when the robbers first enter the house, Kevin goes to hide in the shower. It looks like there is only one way out of the shower. How can Kevin possibly get out of the shower, let alone the bathroom, without getting wet after he turns it on?
Plot hole: One of the children is a witness that saw the man that planted the bomb in Dixie's house. He is said by a policeman to have been playing 'under the porch' and was close enough to make-out the Special Forces tatoo on the bomber's arm. Problem is, Dixie's house had no porch of any kind, and any other home's porch would've placed him too far to see such a small tatoo so confidently. (00:57:40)
Plot hole: Buddy discovers a website, myearth.sat. The site, like Google Earth, contains satellite images of every square inch of the planet. Buddy can see his neighbor's house but not his own house. He decides to cover his house with lights so it can be "seen from space." There is absolutely no reason why the site would show every house in the world except Buddy's, except that the oversight is required in order to advance the plot.
Plot hole: The whole film is basically told as a flashback from Rand Peltzer's point of view. Now he might be able to talk about things that Billy, his mom, or Kate might have told him, but he wouldn't have known about all the other the gremlins did to the rest of the town like killing Mrs. Deagle, the cops, or the gremlin in the mailbox.
Plot hole: In the early part of Fred Claus, the story teller explains that when you become a saint, you become "eternally ageless." However, when you get to the first scene with Santa Claus, he is complaining about the rest of his hair turning white. If he was eternally ageless, his hair would not still be turning white.
Plot hole: Throughout the film we see several characters talk about how there's no Christmas spirit and how nobody believes in Santa anymore. If, in this universe at least, Santa does exist, it's almost impossible for people to think this. If the parents deliver the presents then how do they explain the excess gifts that Santa brings? We know that Michael is on the nice list because Santa shows him towards the end, so Michael must get presents from Santa. There is no way that Walter can't believe in Santa then because Michael gets gifts from him every year.
Plot hole: The sheer distances Kevin covers on foot in one night are outrageous. Between 9pm and midnight he walks from Carnegie Hall to the children's hospital, to 95th street, back to the toy store carrying a large paint can and a large 2x4 (street signs here put it around 59th and 5th), back up to 95th, then all the way back to midtown, to Rockefeller Plaza. One way from W 95th street to around E 59th and 5th Ave. is at least an hour on foot for an adult, he does this 4 times between 9pm and midnight, once while carrying a 2x4 and paint can, once while being chased by 2 adults, and he still has time to set up a house full of traps.
Plot hole: In the yearbook scene Tim barges into Jamie's room and asks her to sign his yearbook, pushes Chris off the bed, and they somehow get their yearbooks mixed up. Tim's yearbook is left in the room with Jamie and Chris, while Tim takes Jamie's yearbook that Chris wrote in with him. When Chris asks Jamie to read the message he wrote in her yearbook, she instead reads the message that Tim wrote to her in his own yearbook. If Tim was asking Jamie to sign his yearbook, why would sign the yearbook with as if he was signing Jamie's. If he was intending to sign Jamie's yearbook, he would have written in the same yearbook that Chris wrote in and not his own.
Plot hole: Jim leaves to attend his family Christmas as evident by his dialogue in the opening scene, and evidently Carl is supposed to be at home to his family in the morning as well, but both are killed by Thomas. When the movie ends with Angela entering the city, it is early morning just before sunrise. Jim and Carl's families would have noted that they were not home on time, and therefore would have had someone searching for them. This makes it implausible that Angela's situation would not have been discovered.
Plot hole: The police are on the trail of a known psychotic and mass murderer. When they turn up at the house of the mother superior, it's evident Ricky has been there, as the door has been cut open and kicked in. There is no way the other nun would have been able to freely enter the house without police escort, or even get out of the police car, as Ricky had not been located and apprehended. The house is a potential crime scene and she would not have been allowed in.