Continuity mistake: In the same shot, note the top of the twin towers are in the clouds - its not a real nice day in NYC. But later when they're on the dock, there's not a cloud to be seen.
Continuity mistake: When Kit gets all the survivors onto the top of the cars, out of the water to keep them "high and dry", Ashley's parents are standing on top of a car next to each other. In one particular shot there's a large distance between them, but in the previous shot they're next to each other. (00:55:50)
Continuity mistake: In the wind tunnel scene, in one shot you can see Sylvester Stallone is facing the small hole; in the next shot he has his body side on. (00:43:20)
Continuity mistake: When the policeman holds the criminal in a choke move, the criminal holds his hands up to the policeman's arms, but, in the following shot he holds his hands up again. (00:46:50)
Continuity mistake: When Sylvester Stallone is in the tunnel with the survivors, he tells everyone to climb on the cars to stay dry, if you watch the female writer in the film closely, she climbs on top of the car twice.
Continuity mistake: When the love interest (I forget her name) finally gets out of the tunnel by the blow-out thing, the water on the surface is all churned up, choppy, etc. Cut to a helicopter shot, where the water is a flat as a millpond.
Continuity mistake: In the scene where the criminals are getting out of the police van, the black woman steps over the steel frame and grabs the seat belt with her right hand. In the following shot she is suddenly holding onto the steering wheel of the van. (00:28:40)
Other mistake: As Sylvester Stallone explodes the grid to come up in the tunnel, the car on top is like a lightweight car, it seems to be stuck to the ground. (00:45:00)
Continuity mistake: When Sylvester Stallone is climbing down the fans, he gets to the last one, looks at the timer, and it says 11, several seconds later you see the clock again, and its only on 10. (00:42:20)
Other mistake: When the tunnel starts to flood isn't it strange how the man hole Sylvester Stallone crawls out of doesn't fill with water? You don't once see air bubbling out of it or anything.
Continuity mistake: When the security guard is trapped underneath the truck, in daylight the amount of water he is drowning in changes. From the front angle he is also most covered in water and from the side angle he has more time.
Continuity mistake: At the start, when all the main characters enter the tunnel Madelyne is in her car, and her window is open, but in the next shot from inside the window is closed. (00:13:45)
Continuity mistake: When the black criminal dies from an injury caused by the huge explosion at the mid river passage, Kit is leaning against the front bumper of a burnt out car, but a few shots later when the camera cuts to a wider angle, the car has vanished and all we see is the old man, Kit and the criminal on the floor with no car, but in the following shot the car reappears again. This has nothing to do with camera angles. (00:51:20 - 00:52:05)
Other mistake: When Sylvester Stallone is about to drop down from the third fan, he attempts to tie it to the hoop in the middle, but instead ties it to the fan itself, in the following scene, if you look closely at the fan above, the rope is now tied to the middle. (00:42:30)
Continuity mistake: In the middle of the film, when Sylvester Stallone gets his yellow bomb wire snagged, if you look behind him Madelyne is on his left, but in the following few shots, she keeps switching from the left to the right, then back to the left. (01:03:45)
Continuity mistake: When we see Madelyne for the first time, she is in her apartment and gets a drink. She then goes to sit down next to her computer, she switches on her lamp and puts something down on the table. In the following shot it looks like she reaches for something with her right arm over her computer, but this was not seen in the previous shot. (00:05:10)
Continuity mistake: When Nord is in the mid river passage on the cellphone, and it cuts to a large object, the large object is sitting on something, which is seen, but when one of its chains breaks loose from the wall, nothing is holding it at the bottom when it begins to swing. (00:47:10)
Factual error: In the beginning of the movie, the explosion in the Holland Tunnel is caused when a car crashes into the trucks carrying toxic waste barrels. In real life, it is against the law for vehicles carrying hazardous chemicals to use any of the tunnels. Even if the drivers didn't know this, which is highly unlikely, they would have been pulled over by the Port Authority cops as soon as they headed for the entrance - lots of yellow barrels would be a bit suspicious.
Visible crew/equipment: When the policeman returns from the Manhattan end, and screams, "There gonna dig us out!", as the car rises behind him, at the left of the screen the large black air bed making the car rise is visible. (01:06:25)
Revealing mistake: Just after Roy Nord gets killed in the mid river passage collapse, we see one of the criminals and Kit come out of the hole, and the black criminal get thrown back by a big flame explosion. When he hits the wall, it seems to bend. (00:50:35)
