When Djebara is confronted by the "musclemen," he overcomes them and disarms one, taking possession of his Walther PP pistol. He then removes the magazine, (not a "clip"), puts it to muscleman's head, pulls the trigger, and nothing happens. Since the Walther PP did not have a magazine safety, this means that the pistol was unloaded with no round in the chamber. Djebara tells him that next time he will do the same with the "clip" inserted, (meaning the magazine). This would have made no difference, as there still would not have been a round in the chamber to be fired, so nothing would happen.
At the beginning, when the burglar is breaking into the safe, he wears a small flashlight attached to one forearm to provide lighting. During the sequence when he get the safe door open, however, the area around him is illuminated at least twice by some kind of hand-held light coming from behind him, even though there isn't supposed to be anyone in the room with him.
During a closeup of Chin Ho driving he makes a sudden right hand turn which causes something or someone (looks like a shirt cuff) to briefly come into camera view as the car lurches through the turn.