Deliberate mistake: This mistake was admitted to in the DVD commentary by the director. When at the embassy, once they open the window, the camera pans up to show a destroyed helicopter on top of the building. This is a mistake as in Moscow, it is restricted airspace for helicopters, with none at all for any purpose to be allowed to fly over the city, not even to land on the American Embassy. However, the director really wanted the visual of a destroyed helicopter on top of the building so added it anyway. (00:41:49)
Plot hole: Everybody jumps into the water and emerges on the submarine except for Natalie. They're wondering where she is when they notice a flare. They realise it's her, and they send a search party. She's hiding on a bus maybe one to two kilometres away from the water. Her going there makes no plausible sense. Makes no sense how she held her breath underwater longer than anybody that they didn't see her and why she would go in the opposite direction of the sub. It was done to prolong the scene. (01:09:00 - 01:18:00)
Plot hole: Towards the end of the movie, the characters use cell phones to determine whether or not the enemy is coming. However, throughout the whole movie, one of the girls has her cell phone, which never goes off even when the enemy is close.
Suggested correction: When she is on the submarine, the engineer hands it to her and tells her he replaced the broken parts and it works now. That is why it didn't trigger for the aliens.
Factual error: During the end where the girl gets her phone back she has a text. However inside a submarine with the hatch shut there is no way for a mobile signal to get through.
Continuity mistake: At the end of the movie when the girl and guy are boarding the submarine, the camera switches to a view where you can see an apartment complex in the background. If you look towards the top you can see someone standing at the balcony and then they move off towards the balcony door. In the next shot the person is gone.
Continuity mistake: In the first few minutes when they are travelling in the taxi, the sign on top of the taxi changes from width-ways (not very aerodynamic) to length-ways when they get out.
