The scene in which the school bus is swung was actually shot by hiring a group of people to sit in a bus, in front of a blue screen, while they swung the bus from a crane. According to the stunt coordinators, the same effect could have been portrayed for half the cost.
Unlike many Hollywood movies, the amount of the ammunition in firearms is depicted correctly. During the chase sequence, Gabriel fires a total of 89 shots from M249 Squad Automatic Weapon, which carries a 200 round box.
Stanley Jobson's hands can be seen typing in many closeups. His fingers constantly hit two keys at once or miss the keys entirely. Hardly the second best hacker on the planet would make this mistake.
When Stan is about to shoot down Gabriel's fleeing helicopter, his shadow is cast to the left of the screen, indicating that the sun is far to the right of the camera. However, the helicopter itself casts its shadow right in front of Stan, indicating that the sun is almost directly behind the camera.
When the FBI agents are watching Gabriel and Stanley, one of them looks through the viewfinder of a camera (Canon XL1s) with a large lens. It is clearly visible that the viewfinder cable is not connected with the body of the camera.