Continuity mistake: When Gust is chatting up Julia Roberts' character (moments before he proposes she sleep with him) he lights a cigarette. The cigarette is definitely lit as you see a puff of smoke (the shot is over his shoulder) the shot cuts to his face and the cigarette is no linger lit. The next shot and subsequent shots it's lit.
Continuity mistake: In the scene in which the CIA guy meets Charlie in the office, the CIA guy removes the cap from the scotch bottle to remove a listening device. In the next shot, the cap is oriented differently on the bottle, yet neither character has touched the cap.
Continuity mistake: When Wilson shouts 'Jailbait' in his office, he is standing at his desk, reaching for a glass with his right hand and holding a yellow note in his left. The camera angle reverses and instantly he is halfway into his chair and holding the yellow note in his right hand. (00:46:45)
Continuity mistake: In the scene in Wilson's apartment, with the attractive girl in only a dress shirt, Wilson is talking to Joanne while the young girl is lying on Charlie with her shirt buttoned. Split second later, her shirt is unbuttoned and Charlie is rubbing her stomach. The time was so fast it would have been impossible for either of them to unbutton the shirt.
Continuity mistake: In the office meeting where Gust meets Charlie, Gust brings a bottle of Scotch. He later tells Charlie the bottle is bugged. Charlie ask him to remove the bug. After he does and he sets the bottle on the desk, the seal is broken and out of line. The camera cuts away and comes back to the bottle the seal is lined up and appears not to be broken.