Continuity mistake: Kevin Costner jumps a subway turnstile as the two CIA agents chase him. The back of his pants are dirty but in the next shot as he runs down the escalator they're clean again.
Continuity mistake: When Susan falls over the railing the way she falls from the front is different than how it looks from the shot behind her. Look at her legs and where they are in relation to the railing depending on the shot.
Continuity mistake: During the room-by-room search in the Pentagon, Kevin Costner deliberately spills coffee on his uniform to avoid the witnesses seeing him. There is a huge wet spot on his left rear and down the back of his pant leg. A few seconds later, after he has excused himself to go to his office to change his uniform, he is seen in the hallway, only now the coffee stain is visibly smaller and more on the front of the pant leg.