Factual error: When the cab that Porter and Stegman is attacked by the Chinese gang members, the cab is shot up and Porter escapes and proceeds to attack the Chinese gang. He uses his .44 caliber pistol he bought in the beginning of the film and a Glock 9mm (I believe). In the course of his attack, he fires about 10 shots from the .44 cal (without reloading, it only holds 6), and about 20 or so from the Glock (holds 17, unmodified anyway). Only when he goes to shoot Pearl, does he run out of ammo. Convenient isn't it?
Factual error: Near the end of the movie, when Porter is forcing his way out of the trunk of the car he was trapped in, he forces his way through the backseat and makes a call from the phone in the back of the car to the phone connected to the bomb in the hotel room. The phone he uses in the car is a rotary phone. These phones can not be used in wireless environments. It was an inaccurate prop.