Continuity mistake: After Keanu commandeers the civilian's car, breaks off the door and jumps to the bus the civilian loses control and heads for the water barrels in front of the divider. Right before he hits you can already see water all over his windshield. (00:38:20)
Continuity mistake: After telling Tuneman that he needs to board the moving bus, Jack pushes the Jaguar several car lengths forward so that he'll have ample distance to smash the door off. Meanwhile, we can see dotted white lines on the pavement between the Jaguar and the bus. But look over Jack's shoulder as he says "Are you insured?" and notice how two pairs of solid yellow lines have momentarily taken place of the white ones. (00:39:05)
Continuity mistake: In the scene where Jack drives the car backwards so he can tear off the door, enabling him into the bus, he slams into a silver car. The very next shot, maybe two seconds later, there is another car driving behind him like nothing happened. (00:39:15)
Continuity mistake: When Tuneman realizes that he's about to crash into some barrels of water near the exit, he ducks for cover but, in the next shot, we see him sitting upright again. (00:40:00)
Continuity mistake: When Payne is in a hideout watching the news unfold on numerous TV sets, he hears one reporter mention that a Los Angeles police officer (Jack) boarded the bus from a moving car. Right here we can see a reflection of Payne in the TV screen, which shows him placing his right hand over his mouth. In the following shot of Payne's face, where he says "Oh would that be you Jack?", his hand isn't anywhere near his mouth. (00:44:20)
Continuity mistake: When Annie drives onto the shoulder, after Jack has come out from investigating the bomb underneath, the bus crashes into a car on a tow truck. In the first shot the tow truck is well inside the white line on the road and it looks like it's half on the grass as well. In the following shot when the bus hits the car, the tow truck has moved to its left and is now on the white line on the road. (00:44:35)
Continuity mistake: At some point before the bus slams into a tow truck and sends a car flying, a large pile of shrubs appears on the curb's edge near the bystanders who start running for cover. (00:46:30)
Continuity mistake: Upon exiting the highway into downtown traffic and blasting through a red light, the bus has a couple of road signs lodged into its bumper which disappear between shots - right before it gets blindsided by a Ford Taurus. (00:47:15)
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)
Continuity mistake: When McMahon is in a helicopter trying to guide the bus from downtown traffic onto a vacant freeway, the bus passes through the same neighborhood twice from one overhead shot to the next, roughly one minute later (pay attention to the recurring trio of flagpoles on the right, as well as a pair of cars that the bus overtakes). (00:48:55 - 00:49:45)
Continuity mistake: When Jack is on the bus and is coming up to the construction site, if you look out of the bus to the left the scenery changes, from having grass on the left before the construction site, to having dirt between shots. (00:49:30)
Continuity mistake: An obvious stunt double is briefly visible pushing a baby carriage full of cans into the crosswalk as Annie unknowingly rams the bus into it. Initially we see an older woman pushing the carriage along after chatting with her friend. In a view from within the moving bus's front window, however, a much younger woman has briefly taken her place for a couple of shots. (00:50:05)
Continuity mistake: Just after the bus driver has been unloaded and Helen tries to get off, Annie shouts "No Helen" at which point Jack turns around and grabs her shoulder to stop her. The shot switches to Dennis Hopper watching TV and then back to the bus where Jack is no longer even close to Helen when the bomb detonates. (00:56:45)
Continuity mistake: In the shot where Payne gives Jack permission to unload Sam from the bus, listen closely to the male news anchor on the immediate right. He reassures his viewing audience that the bus hasn't exploded, although a woman was caught in the blast and fell. This report airs roughly two minutes before the incident even takes place. (00:57:05 - 00:59:15)
Continuity mistake: When Norwood and McMahon break out their maps after hearing about the gap, their platform truck passes a large overhead freeway sign on the right, as seen in a rear window reflection. But a second later, when McMahon insists that the freeway is finished, the sign is roughly 100 yards away instead. (01:02:40)
Continuity mistake: Shortly before the bus gap you can see an END sign at the end of the road. This disappears a second later. (01:03:11 - 01:03:36)
Continuity mistake: Right after the bus jumps the gap, Jack hugs Ortiz. Immediately following you can see the reflection of the stairwell at the front in the mirror. The stairwell and door are both fine, after having been blown off when Helen died. (01:07:00)
Continuity mistake: When Howard Payne calls Jack in the bus and is saying he wants his money, etc, at the start of the next scene the bus can be seen with not only its front doors open, but the back doors are also open with a guy standing on the step in the doorway, even though the back doors haven't been opened yet. This shot is actually cut from the following scene, when Jack gets off the bus, the young guy from the bus stands in the doorway looking out at Jack leaving. (01:07:55)
Continuity mistake: At the airport the black sign on the side of the bus disappears for one shot. (01:09:00)
Continuity mistake: When Jack and Mac are on the back of a truck with the red cart tied to the back of it, when Annie says "I have no idea", Jack and Mac both have their backs against the truck facing the camera, but in the following shot they are facing each other. (01:09:35)
Answer: Ventilation shafts or roof panels.
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