Continuity mistake: When Jack starts wiggling the train's pole, his hands switch places between shots. (01:46:05)
Continuity mistake: When the subway carriage bursts out into the street, Annie's handcuffs slide off the broken pole and in slow motion you can see the pole is shorter than all others. Besides, all the other poles in the carriage are intact. (01:49:15)
Visible crew/equipment: As the end credits are starting, tracks used for a camera dolly can be seen along the left side next to the buildings. (01:50:55)
Visible crew/equipment: When the credits are rolling, a crew member in a gray shirt on the lower left portion of the screen can be seen waving extras into the street. (01:51:05)
Plot hole: When they get Sam the driver off the bus and onto the trailer, it's stressed how important it is to get him to hospital, but in all subsequent scenes, the trailer never leaves the side of the bus and no-one takes Sam off.
Suggested correction: It is unlikely, but they could have transferred him a second time to another vehicle off-screen.
It could've happened during the scene where the older scared woman was trying to leave the bus, and the cops told her to "grab my hand." They KNOW the hostages leaving the bus risks the bomb going off, and they still tried to get that lady off. It's literally these cops' first day on the job.
Continuity mistake: Early in the film, Jack shoots Harry through the left thigh (taking the hostage out of the equation). At the police awards ceremony, Harry is using a cane on his right side and his limp favors his right leg. After the ceremony, in the bar, when Harry gets drunk and starts to leave, he's using his cane on the left side and his limp favors his left leg.
Plot hole: If Jack can speed the train up at the end, why does he not try to slow it down? Even if it can't be stopped completely, using the speed lever to reduce it to the minimum possible would be a sensible course of action. There is nothing to suggest he wouldn't be able to do this as he is able to increase the speed without any trouble. If there was something to show that slowing down the train would be unworkable it would make sense, but seems to more serve as a plot device.
Continuity mistake: In one scene where Dennis Hopper is holding the phone with one hand, he very obvious snaps with the other one just a little bit off camera. The hand holding the phone has all of the fingers, but the off-camera one is missing a thumb. How can you snap without a thumb?
Factual error: When the bus is driving over the gap in the freeway, it jumps off at an angle. And when it lands, it lands close to perfection. If the bus landed at the same angle it jumped off on, the bus would either tip over or the 2 tyres would burst.
Character mistake: When Jack introduces Annie to his boss after the explosion at the airport he calls him Lieutenant McMahon but when the credits come up at the end of the film he is named as Captain McMahon.
Visible crew/equipment: When the police officers are attempting to rescue all the passengers on the bus while at the airport by driving up beside the bus, at one point you get a front camera angle shot showing the people jumping out of the bus onto the police vehicle. If you look closely, you can see the camera man sitting on his chair reflected in the window of the open bus door, he is wearing a white shirt with sunglasses.
Character mistake: At the airport, when Jack is under the bus on the trolley being towed by the truck, an accident causes all the cable on the winch reel to pay out. At this point all that's holding the cable to the reel is a small metal clamp. Jack slews around under the bus for a while, in grave danger of being run over by the vehicle's rear wheels, and then the clamp gives way (in slow motion). The now-free cable shoots toward the bus, and Jack pulls himself off the trolley just as it goes under the rear wheel. If you look at the shot where the cable is flying toward the bus, you can see two SWAT guys standing on the back of the truck, on either side of the winch. Their posture is completely relaxed and casual. Considering that for the past several seconds, Jack has been sliding around under the bus, fighting for his life, wouldn't the SWAT guys be much more excited--moving around, trying to get a better look, giving instructions to the truck's driver?
Factual error: At the airport, Jack attempts to disarm the bus bomb from underneath, on a dolly towed by another vehicle. Meanwhile, Annie must continue driving the bus in circles on the runway at a speed above 50 mph. This scene takes 8 minutes, meaning Annie makes at least 2 laps of the entire 2-mile-long runway, complete with turns at the ends. There is no way that the towed dolly could remain positioned directly underneath the bus through the turns, as Jack would have swung out under centrifugal force.
Factual error: In the scene where Keanu Reeves attempts to stop the subway train, he accelerates the train by pushing the handle forward. In the LA Transit System, the train is stopped by pushing the handle forward.
Factual error: When Sam opens the door for Jack to get on he pulls the handle the wrong way. On GMC buses if you pull the handle back it opens the back door which activates the rear-interlock and that makes the bus come to a complete stop.
Revealing mistake: At the end, when the empty bus rams the freight plane, the wire pulling the bus can be seen. Most obviously in the low shot shortly before impact, where there are several wires/shadows on the ground leading towards a fixed point in the runway beyond the plane.
Revealing mistake: In the scene where Jack and Annie escape from beneath the bus via a trap door, the shot of them skidding across the runway shows a ring on Jack's left hand as it is wrapped around Annie. Jack is not married in the movie, but his stunt double must be.
Continuity mistake: In the last 20 minutes of the movie when Howard Payne is on the train and offers Jack some money, Howard opens the money bag and gets sprayed with purple paint. When Howard climbs on top of the train to fight Jack, all of the paint is gone.