Continuity mistake: In the scene where the plane is blown up at LAX, the intact plane is shown with no mountains in the background. However, the scene showing an exploding plane has a backdrop of desert mountains, presumably Antelope Valley California.
Factual error: Harry is a LAPD SWAT team member. SWAT trains and trains and trains, then exercises and trains some more. Harry would not be investigating the case as shown when he asked to see the files for the last 10 years. If he was on desk duty for his injury, yes, he could be working the investigation. But soon after, he was on the entry team at Payne's house. That would have required more prep work by the SWAT team that Harry would have had to be doing instead of looking through the files.
Continuity mistake: After the first bus blows up, Jack hears the phone ringing. It is a two phone stand. When Jack first reaches for the phone to answer it you can see he answers the phone on the right hand side. To the right of the phone you can only see trees to the right side. In every scene after that, he is on the left hand side phone.
Plot hole: Payne's finger prints would've been all over the elevator, on his shotgun, and near the area where he killed the security guard as he was never shown wearing gloves. Since he was a former police officer, I would assume his prints would've been on file with the FBI and in a multitude of databases. You would think they would've been able to identify him much earlier in the movie than they did by running the prints through all databases of finger prints.
Factual error: In the bus freeway gap jump, a second after driving off the freeway edge, the bus has fallen beneath that edge level of the freeway. It would be impossible for it to have regained altitude to be above the freeway on the other side. It would have hit at best halfway between the wheels of the bus, if at all.
Factual error: As long as gravity is a constant, there is no physical way that the bus (traveling at 68 mph) could possibly jump the level, 50-foot horizontal gap in the freeway. Even at triple or quadruple that speed, the bus would invariably drop vertically by as much as a meter, with catastrophic results.
Factual error: Near the end of the movie, the villain shoots the operator of the subway car. In all rail transportation situations I am aware of, an operator falling from his seat would immediately cause the train to slow to a controlled stop. It's called the "dead man's switch." Obviously does not happen in this movie.
Continuity mistake: Traven drives at high speed down the hard shoulder of the freeway to get to the bus to avoid the big traffic jam. When Traven cannot get on the bus, the black Jaguar XJS is now close at hand, which would have been impossible - it was way back in the traffic and couldn't have got to him that quickly.
Continuity mistake: When Annie swerves to avoid the schoolteacher and the kids, in the previous shot of the kids and the schoolteacher, they have already stepped out onto the road and are crossing, yet when the camera cuts to a view looking out the bus the schoolteacher and the kids are just stepping off the curb and walking across. (00:48:50)