Continuity mistake: The scene after Jasmine's club pole dance, she is with her girlfriend in the dressing room. She is warning her girlfriend not to go to the alien rooftop site. Jasmine walks away undressed, but comes out a moment later with her shirt and pants on, and though she put her clothes on over her dance outfit it is still too quick to accomplish in that brief moment. (00:36:25)
Continuity mistake: David calls Connie at the White House and she walks toward the divided pane windows, then pulls one curtain to the side. In the exterior shot facing her, the pane's white grille is between the two sides of the curtain, but in the next interior shot looking out, there's only clear glass, though we should see the grille, just as we see both sides of the curtain with her hand holding the right side. Then, in the next exterior shot facing her, it's back to the original with the visible white grille. (00:38:25)
Visible crew/equipment: When David reaches Connie on her cell phone in the White House, as she walks away away from the wall to head towards the window, a crew member (complete with water bottle and utility belt) can be seen on the lower left portion of the screen, before he quickly scrambles away. (Only visible on VHS and fullscreen DVD.) (00:38:27)
Continuity mistake: At the club, in Jasmine's dressing room, there are either two nail polish remover bottles beside the TV, or two white bottles - one large, one small, depending on the angle of the shot. (00:38:35)
Continuity mistake: Close to the beginning when David is outside the White House and puts the device on top of his car, in one shot you can see him put the device on the top and put his hand down, and in the following shot he's putting his hand down again. (00:40:10)
Audio problem: In the car with Julius, we hear David say, "Hey, hey slow it down," but his mouth actually says, "Hey, hey what have..." (00:40:25)
Continuity mistake: When David is explaining to the President about the aliens' intentions with Earth's satellites, he draws two lines that start at the destroyer and go off straight both edging off Earth. But when he places the paper back on the desk to draw in the satellites, the left lines have risen away from the Earth. (00:41:00)
Continuity mistake: When the White House is being evacuated, as Connie runs down the stairs in the shot facing her, she is speaking with a woman to her right, but in the next shot from behind the woman has vanished. (00:42:30)
Continuity mistake: When the White House is being evacuated, in the shot from behind as Connie rushes to the chopper, at her side she carries a briefcase in her left hand, but in the next shot facing her nothing is in her left hand (viewer's right). (00:42:50)
Revealing mistake: When Marty is stuck in traffic in his car, trying to get hold of his therapist, there is an overhead shot just before this one showing traffic with a few taxis. This traffic shot is flipped - note the steering wheels on the right side of the cars. This particular shot is shown again, but not flipped, just after the Empire State Building blows up. (00:44:00 - 00:47:10)
Continuity mistake: Although the 'line of sight' scene has been mentioned, in one particular shot from behind Jeff Goldblum, he has his right hand out with the piece of paper in it, but when the shot switches to in front, he has his hands on his hips. (00:45:10)
Continuity mistake: When the President is evacuating the White House close to the beginning, in the first shot you can see him and his daughter just in the doorframe, in the following shot they are about 5 feet away from the door. (00:45:15)
Factual error: When the alien ship over New York blows up the Empire State Building you see the blastwave spill out in the street in front of the Empire State Building. This is in that part of the city that's built in a grid pattern. In front of the Empire State Building there's just another building, not a street where the blastwave and debris can spill into. All the people who are way down the street, looking at the building being hit by the beam just can't be there. (00:47:00)
Factual error: When the Empire State Building gets blown up, look to the right of the picture. The building next to it is the Citicorp Center. That is not right because Citicorp Center is on Lex between 53rd and 54th, while the ESB is on 34th and 5th. (00:47:00)
Factual error: The firewall that destroys Washington DC is all wrong. When the destroyer blows up the White House, as in NYC and LA, it would have created a ring of fire that would have spread outwards. The White House is in a North Westerly position from the Capital Building, so when the fire wall hit the Capital Building, it would have hit from the side - but, instead, it hits from the back/front. (00:47:30)
Factual error: The Capitol's dome crumbles like stone, but it's made of iron. (00:48:10)
Factual error: When Jasmine is running in the tunnel, she kicks open the door just in time to save herself, her son, and the dog. The terrible fireball then goes right by them. They are just inside the open door, with fire and debris flying right past it. While the fire and debris might not spill in, the heatwave would still fry them. It is also likely that the fire would deplete the limited oxygen of the enclosed space. (00:49:50)
Continuity mistake: When they all board Air Force One, David and his dad are led to a rear section of the plane. The corridor they walk down is on the left of the plane and when they emerge it's on the right, as though they used the same section for both shots. (00:50:20)
Revealing mistake: When the aliens attack LA, there is a shot of red and silver cars. The same cars fall three times onto other cars, from three different angles. (00:51:00)
Revealing mistake: In the scene where Jasmine, her son and her dog are trying to escape by jumping out of a cab and running, she turns and looks toward the explosion. You can see that she is carrying a very big, very stuffed mannequin. (00:51:30)
Answer: Remember that the aliens had to interface with our satellite computer code first...David simply "reverse engineered" the code to create the virus. When it was uploaded, they didn't have enough time to combat it.