Deliberate mistake: Gandu Three Echo, the clone who hits the screen showing the first lottery winner in the movie, complains that he has been around for 7 years and never won the lottery. However, McCord explains later in the movie that the last name tells how old the clones are. Lincoln Six Echo is 3 years old because he is in the Echo generation, and the Delta generation (Jordan Two Delta) is 4 years old. Going backwards, this would make Charlies 5 years old, Bravos 6 years old, and Alphas 7 years old. Gandu Three Echo should have really been Gandu Three Alpha. (00:05:55)
Deliberate mistake: When the New York subway is flooded the interior shot shows the station is Wilshire Blvd. Wilshire Blvd is in Los Angeles and the film clip appears to be stock footage from the Universal Studios Tour ride.
Deliberate mistake: When the Matoban delegation arrives at the UN, it shows the motorcade entering the circle in front of the UN Secretariat building and stopping at the revolving doors right at the front the staff entrance. Diplomats' motorcades always continue on to the delegates' entrance under a protective tent in front of the GA building so as to allow VIPs to alight from their vehicles to prevent potential snipers from having a view of them. The very next shot of the ambassador shows him riding the escalator, which is at the delegates' entrance, going up to the General Assembly building. This would not have been possible unless they made him walk about 300 meters outside in broad daylight. No chance of that seeing he was already being protested on 2nd avenue all the way from the Queensboro bridge. Obvious reason for this error: The shot of the delegation getting out of the cars looks far better in the open right in front of the UN secretariat building rather than inside a protective tent.
Deliberate mistake: This was probably done intentionally to make them more visible, but the bullet holes left in the stairwell wall by Bart's handgun while he is chasing Danny during the movie's climax look to be about the size of golf balls. Typical handgun calibers aside, just looking at the size of the clip he's loading into the gun and seeing how many rounds it holds, those rounds would have to be much smaller than the holes the bullets made.
Deliberate mistake: In the beginning, the police chief says "The six members of the family were found last night, in bed, shot and killed." As he says this, look to the left of the screen. In the background, the real Amityville house (dark brown with white windows and trim) is shown instead of the house used in the rest of the film. That segment was from actual news footage of the murders from 1974; apparently, the director didn't want to recreate it.
Deliberate mistake: When Amanda is watching the guy cut the skin from the back of his neck, you can see the same shot repeated twice at the beginning and end of the ordeal. It is the zoom in shot of her just as she is about to start shaking her head. (01:16:50)
Deliberate mistake: On the map showing the location of all the 'Camel Hump' refuelling blimps, none of them are anywhere near the countries EDI visits in the film - the nearest one is more than a thousand miles away over the Pacific.
Deliberate mistake: When the tribe does the ceremonial dance to bring the crow back to life, you can see the same shot of the bird leaping up twice.
Deliberate mistake: When Constantine comes out of the library after speaking with Gabriel, he stands beside Angela and none of them cast any noticeable shadows on the door and walls behind them. When it cuts to a shot above them, shadows are more being cast behind them. This is probably because of different light settings on the set. (00:23:35)
Deliberate mistake: The chainsaw cuts off the German torturer's leg and it manages to move all by itself a few feet within a few seconds, when it would just run and slowly move and stall as seen after it moves. Obviously done to increase the tension. In addition, the chainsaw looks very clean with no blood dripping and bloodstains on the floor.
Deliberate mistake: It's a really fun visual, but when the bad guys enter the kitchen and get swarmed by African-American waiters in white tuxedos, one can't help but wonder how it could be that Darius was almost the only waiter on the floor up until a moment before - there were a couple others, mostly white dudes, while now we see about 20 people, all of color, coming out at once. The disproportion is huge, it's not like dinner is being served. (00:39:30)
Deliberate mistake: When Dead Reckoning is firing the missiles at the end (towards the crowd that's being eaten by zombies), you can tell that they repeat the same shot of the missile firing three separate times, even though it's supposed to be three different missiles. (It's the shot of the exhaust coming out of the back of the launcher.) They try to mask it by cutting a little earlier or later each time... but it's obvious.