Factual error: When Sawyer and Cale take Cadillac One ("The Beast"), they eventually want to shoot a rocket launcher at the fence. Sawyer wants to do this while hanging out of the window. The real Cadillac one is bullet proof and have several layers of glass with the final one softer not only to prevent the bullet but the more deadlier threat glass pieces. Only the driver side can open approx 3 inches.
Continuity mistake: When John and Emily start their tour, the guide asks them where they're from. After that, they start to walk towards one hallway. John and Emily are in the back. The next shot, they're in the front of the pack. There would not have been enough time for this to happen.
Continuity mistake: Towards the end of the movie when John is talking to the President after he got shot in the watch, John has a wound on his right arm. A few minutes later when John is outside the White House you can see his wound is different, it's bigger and there's lots more blood.
Revealing mistake: After the explosion - I think the first one - the terrorists are going around killing the security men and taking their weapons - with one security man down and his gun on the floor, there is a yellow marker under his gun, we see the marker when the gun is taken. Maybe the yellow marker is there as a position marker, so the actor knows where to put his gun after he has been "killed" and fallen down.
Factual error: Shortly after President Sawyer and John have to climb up the elevator shaft in the White House, there is a shot of several motorcycles riding in the front of a motorcade. The motorcycles are BMW R1200RTs. The Capitol Police, DC Metro Police and the Secret Service use Harley Davidson motorcycles.