Factual error: The Russians stopped using steam locomotives in the 1970's. So bringing one out of retirement in 1997 to haul nuclear warheads would mean that your highly secret nuclear train would be well known among rail enthusiasts for weeks before.
Continuity mistake: As Nicole walks across a plaza with Clooney to meet the Russian spy, she is wearing sheer stockings and low pumps. As she walks off the plaza she is wearing knee high boots with fur tops.
Factual error: When they download the requested file from the computer you can read ie."600 Dantensatze in Databank." Correct is: "600 Datensätze in der Datenbank." At the same time when the bad guys try to identify Clooney you can read on the screen the German "Gerwicht" for weight. Correct is: Gewicht.
Continuity mistake: In the first scene that introduces us to George Clooney's character, we see him in front of some sort of Judicial committee. The first scene he wearing gold leaves which indicate the rank of Major, although in the movie he is a Lt. Colonel. Then very next scene when we see Clooney he is wearing the correct rank.
Continuity mistake: When Julia is giving a brief to the people in the room about terrorists and such, Tom interrupts and walks over to the screen. In this shot Julia is raising her hand/hands and pointing at him, yet in the following shot her hands have not moved from her side only her head has moved to the mic. (00:23:35)
Plot hole: Where are the police? The chase takes about 8 minutes in the centre of the biggest city and capital of Austria, not to forget the using of the guns.
Continuity mistake: When Clooney is fighting in the truck on the bridge, he is pulled up by the helicopter. As the camera follows him, you can see him pulled up at least 10 meters. When cutting himself from the cable he falls back into the car. but only about 3 meters.
Continuity mistake: In the fight scene between Tom and Alec in the truck that is hanging over the edge, when Tom is pulled up by the helicopter he cuts the rope and lands on his back. He actually loses his knife which is in his right hand, yet in all following shots its reappeared back in his hand. (01:15:05)
Plot hole: When the diesel train stops in the tunnel, one of the soldiers tells another one how far they are from the spot where the nuclear detonation will take place. Do the math: the distances don't work out. At least one of the trains would have to do over 100mph AVERAGE to put enough distance between them. Military precision, indeed.
Plot hole: After Vlado was shot and his brother (the one with the bomb) was carrying him, there's no way Tom and Julia shouldn't have been able to catch him. He was MUCH slower carrying Vlado and they should have been able to catch up to them in no time. And there were other law enforcement following DeVoe. There was only one way out of that alley. Why weren't they at the entrance?
Continuity mistake: When Tom and Julia are in Julia's office, Tom sits down while Julia is on the phone and begins to read the small card from the flowers. In one shot Tom's three/four fingers are on the back of the card, then in the following shot he is holding the card at the edge with just his fingertips on the card. (00:26:55)
Continuity mistake: When the bomber walks on to the streets of New York, he passes a violinist standing next to a tree. There is a man with a red coat sitting on the trees ledge and a black man standing next to him, yet in the following shot (perhaps 1 second later) the man sitting on the ledge and the black man are both standing up about 4 feet away from the tree. (01:33:00)