Revealing mistake: At the end when the Monk With No Name has turned old and is walking away from Kar and Jade while waving to them (without looking back), you can see a finger on the left side of the screen covering up the corner and side of the lens. This is for sure in the wide-screen DVD version.
Continuity mistake: When Bad Girl/Jade tries to see Kar at the cinema and he isn't there she leaves a note. Through the scene as she writes the note, her hair keeps moving from in front of, to tucked behind, her left ear depending upon the angle.
Continuity mistake: When the monk with no name is fighting his master, there is a shot where they are both holding opposite ends of both poles and spinning in the air. In the close up of the monk, he is spinning in the wrong direction.
Continuity mistake: In the scene where Jade and Kar are driving in Jade's SUV to rescue the Monk from the German, Jade reaches down to hold Kar's hand, but when the camera angle changes, she has both hands firmly on the steering wheel.
Continuity mistake: When the Monk tells Kar that he's going to help him with his fighting skills, you see the other 2 Monks standing behind them, one in front of the other and one of them puts his hand on the shoulder of the other. The camera angle changes and you now see them standing side by side.
Continuity mistake: In the scene where the old German guy finishes looking at himself in the mirror and goes to read the rest of the scroll, he's saying the words but he's not reading anything. He's just looking at the vital signs of one of the monks.
Continuity mistake: When the Monk does his flip to avoid getting hit by the car, the bad guys get hit and their guns go flying in the air. You see the guns spinning in the air and they are facing the opposite direction from each other. The camera angle changes and you see the Monk grabbing the guns and they are now facing the same direction before he grabs them.
Plot hole: When the monk and Kar break into the mansion, the monk flips up onto the wall and pulls Kar up and over. The whole time they are doing this, there is a security camera on the wall that can blatantly see the whole thing yet no one does ANYTHING about the intrusion. Security was obviously slacking off that night.
Continuity mistake: When Kar goes back to the warehouse to find the Monk, he pushes the door open and the 2 women hold up swords to his chest. The camera angle changes and the sword on the right is now on his shoulder. The camera angle changes again and the sword is back against his chest. You also see him standing with the doors almost closed against him when they were fully opened in the previous camera angle.
Continuity mistake: When the bad guys are chasing the Monk and Kar across the street, you see a BMW almost hit them and it stops in the street. The camera angle changes and you see the bad guys crossing the street and the BMW is now gone and a different car almost hits them in the same place the BMW almost hit the Monk and Kar.