Corrected entry: Hans and most of his men arrive on the 30th floor party and begin firing. Upon hearing the shots, McClane grabs his gun and is able to sneak into the nearest stairwell and climb up a few flights of stairs (he checks and passes the 31st floor, where a few more of Hans' men are spotted wheeling supplies) before finally arriving at the 32nd floor to begin seeking help. For essentially the remainder of the movie, McClane remains "above the danger zone", so to speak. However, it is fair to theorize that when McClane initially reached the stairwell undetected, he could have also descended to any number of other floors to then seek help. Even if many of the lower floors may not have been open (locked, not finished, etc.), McClane could have simply descended as far down as the main lobby (and out the front doors). Remember, Hans and his men were not aware of a straggler at first, and in theory all McClane would have had to do is descend the stairs to the main floor and get past the lone terrorist acting as the "security guard" at the desk.
Corrected entry: As the terrorists enter the building, they slide a flashbang up to the guard which explodes, and then the man is shot by one of the terrorists. About a half hour later when Sgt. Powell is dispatched to check out the plaza, he walks in the first floor and right up near the same elevator area, supposedly sees nothing, then leaves. We can assume the terrorists got rid of the guard's body, but there must have been other obvious evidence of a shooting/explosion in that hallway area (blood, wall or floor damage, remnants of an explosion) which Powell would have noticed.
Corrected entry: When McClane enters Holly's office, a crew member is reflected in the mirror. (00:12:05)
Corrected entry: McClane sends the elevator down to the 30th floor with Tony's body in it and gets on top of the elevator. The terrorists are there, standing about, discussing the body and that they must now tell Karl that his brother is dead. Why would they then press the button for the 32nd floor (the top floor) without getting in? That happens only so that Bruce Willis can get to the roof for the next scene.
Corrected entry: When John is on the roof trying to radio for help he connects with a woman from an emergency help line, why does the woman not believe him when he tells her about the huge emergency? Not in a million years would a person from the emergency help line not believe you when you call them with an emergency, even if it sounded like a child making a prank call ordering a fire-truck to his friend's house and they could hear the child giggling while he's saying it, they would still have to send someone out. John is screaming at the woman for help and she still doesn't believe him.dan coakley..
Corrected entry: The C-4 explosive would need an electrical charge to cause the explosion. The chair and computer monitor or fall wouldn't cause the C-4 to detonate.
Corrected entry: When the FBI agent is telling the worker from the power company to shut of the power, the worker says that the power will be out for several city blocks. When the helicopter is taking the agents to the Nakatomi building, all of the lights are on in all of the surrounding buildings.
Corrected entry: A few of Gruber's henchmen set up the rocket-launcher to blast the armored police vehicle. As one of them swings the legs of the launcher down, another uses a 'Hilti' gun to anchor the leg in place. A 'Hilti' gun is a construction device that uses gunpowder (usually a .22 shot) to 'blast' a nail into very hard material such as concrete. The nail has to be manually loaded into the front of the gun for each shot before it can be used, however the guy using the gun never loads a nail into the gun. As it is, the result would be worthless.
Corrected entry: At the end of the movie, Richard Thornberg is trying to interview John and Holly. Holly socks him in his nose and he is grabbing it in pain. The next shot, as John and Holly enter the limo, he is talking to a camera normally as if nothing happened, then the next shot, he is suddenly holding his nose again.
Corrected entry: McClane is in the bathroom picking broken glass out of his feet, and the whole time he is having a conversation via radio with officer Powell. However, the radio is just sitting on the counter-top while the conversation continues. This is not possible since the key (talk) button needs to be depressed to transmit.
Corrected entry: McClane uses the festive holiday tape that was used to wrap gifts to tape his pistol to his upper back before the big finale. Considering how much blood, grime and sweat McClane had on him, that tape would never have stuck to his skin, especially considering that it is only wrapping tape, not some kind of industrial tape like duct tape or anything stronger.
Corrected entry: The electromagnet locking down the vault could not have simply deactivated if the power was cut. The steel used in the construction of the vault would have developed into a permanent magnet (remanence) thus preventing the vault from being opened. Removing this remanent magnetism is very difficult, one of the simpler ways is to heat the material to its curie point, which around 1500 degrees Fahrenheit (816 degrees Celsius) in 9.0% carbon steel, the terrorists did not do this or any other method to remove the remanent magnetism.
Corrected entry: When McClane confronts Hans and Eddie in the vault, he shoots Hans and Eddie in quick succession with his 9mm handgun. One problem, a 9mm round wouldn't go straight through someone even at close range, so where did the bullet hole in the window behind Hans appear from?
Corrected entry: During the scene where agents Johnson and Johnson are flying in the helicopters, they are obviously flying in an AH-64 apache helicopter type of gunship. However when the terrorists blow up the Nakotomi roof top and one of the helicopters explodes, the helicopter used in that scene is noticably different, more like a Bell Huey type chopper.
Corrected entry: John McClane opens the elevator doors and uses an axe to hold them open. Then he ties C4 explosives to a chair, uses a computer to hold it in place and pushes the makeshift bomb down the shaft. The explosion is so powerful that it takes out a good part of the torso of the building, but when the fireball gets to John the axe remains in place when it should have been blown away. (01:13:25)