Continuity mistake: When Jack is briefing the President, he draws a line on a map of the U.S. and tells the President to have everybody south of that line evacuated. The shape of the line changes three times between shots. (01:04:20)
Continuity mistake: Just before the huge wave hits the library, we see that Laura cuts her leg. She cuts it on the side of the top part of her leg. Later in the movie, when her trouser leg is pulled back to reveal the wound, it is now on the front of her lower leg. (00:47:50 - 01:30:15)
Continuity mistake: When the tidal wave is hitting Manhattan, and the camera cuts to Laura walking behind the black woman and the cop, the woman panics and turns to her left to look at Laura, but in the following closeup she turned to her right to look and talk to Laura. (00:47:50)
Continuity mistake: The first time we see the black bear cage, the sign (and the entire shot) is a reversed image. Twenty five minutes later, we see the black bear cage again and the sign is correct. (00:20:35)
Continuity mistake: After Sam's phone call to his dad, when Jack holds his wife with both hands at her cheekbones the position of her hair changes from under his hands to over, between shots. (00:56:20)
Continuity mistake: When Sam and his two teammates are on their way to NYC for the competition, the airplane gets hit by turbulence. Two attendants go to the back of the aisle with the drink cart, when the plane starts to shake, and in the long shot of the aisle (from the head to the back) one of them is in front of the cart and the other one is behind. However, both are behind the cart in the close up, when they try to prevent the cart from hitting anybody.
Continuity mistake: When Jack is trekking north to Manhattan with two of his colleagues, one falls through a glass ceiling and the other cuts his right hand trying to save him. Despite the fact that we see his hand bleeding profusely, you can see in the subsequent scene that his right hand is just fine.
Continuity mistake: At the Hedland Center, when Dennis wakes up Simon from snoring, in the background Simon lifts himself up from the chair, but in the next shot he is already at the coffee machine. (00:09:20)
Continuity mistake: When we see the news report on the TV, you can see that people are taking bottles of water from the shelves. Beside the TV you see a person's hand on the right side of the TV and a black tea flask as well. In the next shot the person's hand is much further away from the screen and the tea flask has also been moved to the opposite side of the TV. (00:35:15)
Continuity mistake: Just after Jack comes out of the New Delhi conference, he is talking with Terry Rapson. At the right of the screen at the stand, there is a guy with a red hat/turban and scarf and no other people behind him with turbans. However, in Terry's close-up the man wearing the red turban has vanished and there are a lot more people in the background wearing turbans. (00:08:05)
Continuity mistake: As the massive tidal wave is rolling through Manhattan, when it cuts to Sam looking at Laura from the steps, the two taxis in front of the library are further away from each other, than in the following shot when Sam has to jump on the cars just to get over them. (00:48:00)
Continuity mistake: When Jack and Lucy are talking about Sam failing class on the phone and Lucy says "I don't have time to talk about this right now", it shows Sam eating and a milk pack with its opening pointing left. When it cuts the opening is pointing right. (00:12:25)
Continuity mistake: When the two men at the start of the film are saving Dennis Quaid from falling, you can see Quaid reach for one of the others' hands, then that guy grabs him with both hands, but in the following shot, Quaid is holding the hands of both men. (00:05:25)
Continuity mistake: When the huge tidal wave hits the bus you see a man standing on top of a taxi, number 7Z22, which gets crushed by the water. Moments afterwards you hear the French woman saying that she left her bag behind. If you look on the right side of Laura you can see a still intact taxi with the number 7Z22 on it. (00:47:30 - 00:48:00)
Continuity mistake: At the end of the movie, when they are all in the helicopter, it cuts to a view of them looking out the window. In this shot, the black actor is sitting next to the window, on the other side of the helicopter, but in the following one, he has suddenly switched seats, and is no longer sitting next to the window. (01:49:40)
Continuity mistake: When on the plane and there's the major turbulence Sam's hair flops over his forehead.Then he looks at the wing and there is no hair on his forehead but in the next shot of him his hair is back messed up. (00:17:55)
Continuity mistake: When Lucy is saying good bye and hugging her co-worker, she puts her arm over the co-worker's shoulder. When it cuts, Lucy's arm is gone and when it cuts it's back over her shoulder. (01:13:15)
Continuity mistake: As the tidal wave is heading towards the library, the homeless man picks up his dog and runs towards the library. In the next shot his dog is still on the ground.
Continuity mistake: When we get to the public library the first time there is a shot from behind the homeless guy - he has his hand on a cart. When it cuts to a front shot his hand is off the cart. (00:44:25)
Continuity mistake: When T.J. is talking with the homeless black guy who is sitting on the floor telling the student how to keep warm, the guy throws the student a book to rip up and make himself warm. When he throws the book, the student is grasping the book at the bottom with his left hand, but in the following shot his left hand is at the top of the book. (01:16:30)
Answer: Possibly because it was the closest building with height to it as they are about to be hit by a gigantic wave of water. There was no snow yet, so I don't believe burning books or snow was on anybody's mind yet. It turned out to be a great idea as snow soon starts to fall and those books were literally a life saver.
Susan D. Santos