When the Rock finally starts using guns, there is one shot where the three holes in his tee shirt are on the right side of his chest, because it is a flipped shot. The holes are on the left side of his chest in every other shot.
California Govenor and former action star Arnold Schwarzenegger makes a special guest appearance in this movie. When Beck first arrives at the night club, Arnold walks right by him and tells him to "have fun." Arnold had just become Govenor and knew he would not be acting for awhile so this was his way of passing the torch to someone he felt would take his place as the future of action movies.