Continuity mistake: In the scene when Yuri's daughter is getting away from the hotel, the color of the chopper changes from green to brown between shots.
Visible crew/equipment: When walking into the vault at Chernobyl, a cameraman is reflected in one guy's gas mask visor. (01:02:05)
Factual error: It is not plausible that the tail rotor blade of the helicopter can destroy large parts of a building without being damaged. (01:24:40)
Continuity mistake: Throughout the blue van chase, the damage to the van is constantly changing/repairing itself.
Continuity mistake: When John and Jack are discussing if he meant Chernobyl, the blood on Jack's face disappears instantly. (01:00:50)
Continuity mistake: At the end, Jack and John fall into the pond and get soaked. As they walk out of the building their clothes are completely dry. (01:29:15)
Continuity mistake: During the chase with the blue van, it keeps changing model. Starts with a van with high roof, than low roof, high roof again. And this goes on and on.
Other mistake: Komerov gets shot in the arm at the start of film, however, he is able to use his arm perfectly even straight after being shot. (00:34:30)
Continuity mistake: At the end, the wreckage of the helicopter changes position instantly. Note the position where the rotor blades are. In one shot they are on the side, then on top. (01:29:35)
Continuity mistake: In the car chase, the blue van is hit and the left side headlight dislodges and is dangling down for most of the chase. But in one far shot where the van is taking a turn, it is suddenly switched to the right headlight that's dangling. (00:23:00)
Factual error: When Yuri's daughter is getting away from the hotel tower, she has to walk to the next building located in front of the tower's window to take the chopper. It should take several minutes, but she does it in a few seconds. (00:48:25)
Plot hole: When Jack and John are on their knees in the hotel, with their hands zip-tied behind, Jack manages to use a hidden knife to cut his bindings and starts kicking bad guy butt. Jack immediately joins the fray but a careful review shows that at no point did John use his knife to free Jack.
Continuity mistake: During the opening chase the chase goes along the river from left to right as you look at the screen. They make a turn and now go from right to left as you look at the screen, along the same river.
Revealing mistake: When the armoured truck hits the first parked car you can see the smoke appear at the side of the car and a jet of smoke when it flips from the air cannon.
Revealing mistake: In the opening chase with the armoured truck it comes up behind a blue car that is already dented on the near side, which is the side it slides round to so the truck hits it. It then gets pushed onto a silver van that is completely wrecked from previous takes.
Continuity mistake: The mobile tank rips a door nearly completely off a blue van. When John hits it, there is less damage to the door. (00:22:50)
Continuity mistake: When we first see John, he is in the police shooting range. He has on protective head phones which he takes off and sets on the table in front of him as the other cop comes in. He and this cop talk about Jack, and when they finish, they shake hands. The mid range shot of them shaking hands shows the head phones still on the table. It then cuts to a far shot and now the head phones are gone while the two finish the hand shake. Careful which table you are looking at, as the angle makes it confusing. The head phones were on the table with the red thing on its left side. (00:06:50)
Continuity mistake: When John gets out of the taxi, the window is open. When he closes the door, the window is shut. (00:12:00)
Plot hole: When John has Yuri pinned to the uranium boxes, Yuri reaches into his coat and turns on his walkie talkie so his daughter and minions can hear. John McClane doesn't notice and he is right there. There are two things wrong with this. We hear the beep the radio makes when it is turned on, and it was loud enough that John and Jack would have easily noticed. But even if they didn't hear it, there is another issue. John is a New York cop, or even a detective. As such, he would have extensive training for dealing with armed men, and he would have noticed Yuri reaching into his coat. Even if he didn't hear the radio beep, he would have stopped Yuri's hand or done something, assuming Yuri was reaching for a gun. (01:18:15)
Answer: His name was Anton. He was an associate of Viktor Chagarin. Jack, although lying, said Yuri Komarov sends his regards. Chagarin and Komarov were former partners and Chagarin was the one who got Komarov put in jail. By Jack saying Komarov sent him, it made it seem like Komarov was out for revenge on Chagarin (by attacking his associates). The courts offered to reduce Jack's sentence for testifying against Komarov, which allowed Jack to get close to him and help him escape.
Bishop73