Visible crew/equipment: When the bus is about to jump the bridge, you can see that the bridge is flat, apart from the broken part, but when the bus jumps over the bridge, there's wood and stuff piled up at the end, making it "kick". (01:03:35)
Factual error: When the bus jumps the gap in the freeway, the front wheels rise into the air while the rear wheels are still in contact with the roadway (that has a very slight upward slope). Since its trajectory is fairly flat in the movie (unlike the ramp used to actually film the stunt), the front of the bus would fall well short of the other side. Further, the impact of landing would render the bus unable to move (which is exactly what happened to the bus used to film the stunt). (01:03:40)
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)
Revealing mistake: When Jack is on the phone with Payne at LAX, a Suburban carrying Lieutenant McMahon and Norwood skids onscreen from between some orange cones. But tire tracks from earlier takes can be seen on the pavement. (01:10:00)
Continuity mistake: The Suburban that swerves onto the LAX runway to retrieve Jack has no scaffold equipped on its driver's side, but we know for a fact that moments later Jack actually exits the bus and steps safely onto one. Somehow the Suburban has managed to gain a scaffold at cruising speed, but this couldn't have possibly happened unless a different, identical-looking vehicle with a scaffold pulled up at some point during the scene to take its place. (01:10:05 - 01:11:15)
Audio problem: When Jack tells the bad guy he wants to get off the bus, he says "it's not against the rules." The bad guy then says "All right, but I want you back real fast." Look at his mouth while he says the line. You can see that the talking isn't similar to the moving mouth. This is because Dennis Hopper originally said "in ten minutes" instead of "real fast." Since Jack was gone longer than 10 minutes, the line was re-dubbed to something less specific. (01:10:37)
Visible crew/equipment: A film truck is reflected in the bus's bumper when Jack exits and steps onto the Suburban. (01:11:15)
Continuity mistake: The 2 SWAT team members are not visible on the preceding truck between two shots. (01:12:55 - 01:13:32)
Audio problem: When Jack is under the bus trying to diffuse the bomb and the piece of rubber hits him he says "F*ck Me" but his lips don't move. (01:14:30)
Visible crew/equipment: When Harry's colleague hands him a printout of Howard Payne's newspaper article, a boom mic reflection is visible on the window right above the bomb schematic diagram. (01:15:15)
Revealing mistake: In the scene where Jack has come back into the bus from being underneath it, he is talking to Annie about losing gas, if you watch closely he says "Mac" without pressing his button to call him first, then in another shot you see him press it when he starts talking to Mac. (01:15:50)
Continuity mistake: When Jack is inspecting the bomb from a red trolley connected to a tow truck, a spool of cable unwinds and breaks free from its clamp, leaving Jack to fend for himself. Soon, McMahon and Norwood are riding alongside the bus trying to see if Jack is okay, but notice how the cable has reattached itself to the empty spool. (01:16:30 - 01:17:30)
Revealing mistake: When Ortiz first sees Jack stranded beneath the moving bus, he lifts his head to tell Annie. But the pavement, as seen through the bus floor's opening, is completely motionless. (01:17:25)
Continuity mistake: When the cops arrive at Payne's house, the front passenger door of the silver car closes. However, in the next shot it is open. (01:19:45)
Visible crew/equipment: During the passenger transfers at LAX, a cameraman is visible through the bus doorway two shots before Annie glances over her right shoulder twice. (01:27:35)
Continuity mistake: When Jack starts tying a rope to the access panel, he faces the back of the bus initially but manages to turn completely right between shots, facing the side windows all of a sudden. (01:29:20)
Other mistake: In the scene where Jack and Annie escape from the bus after they have gotten all the passengers off, when Annie is tying up the wheel, if you look closely, you can see that the gas gauge is at about 3/4 full. Isn't the gas tank supposed to be almost empty? (01:29:35)
Answer: Ventilation shafts or roof panels.
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