Factual error: When Antonio Banderas gets shot with the dart in the forehead there are two reasons why that wouldn't work - 1) There isn't any muscle tissue and the skin is too thin for the dart to stick most likely. 2) The tranquilizer would never take effect that quick unless it was injected into a muscle where the blood supply is greater. (00:53:55)
Continuity mistake: In the scene where the little boy is guiding Agent Sands to the center of the city, watch Agent Sands' right hand. In one shot, his hand is empty and he is holding on to the wall as he walks, but in the shot where the boy turns around to look at the guy who is following them, you can see a gun in his hand. Shortly after that, his hand is empty again and he reaches in his pants and pulls out the gun.