After shooting the mysterious "machine gunner" at point blank range to end the Teahouse shoot out, the shot Tequila fired leaves a gory glob of blood on his face. However, when Tequila rushes to the side of his fallen partner, Benny in the Teahouse, the blood on Tequila's face appears to be only a small dried smudge on his face even though it's supposed to be just moments after Tequila shot the thug. While Tequila could've wiped his face, there's less kitchen flour on his face and clothes than a moment ago as well.
Location and the position of Benny's (Tequila's partner) body in the Teahouse. When he was shot, he was inside the kitchen with the door entering the kitchen to his left. Yet after Tequila comes to his side after the shoot out, Benny is outside the kitchen on the floor in the dining area. That would mean that as he was being shot, his body would have to have had to make a left turn to get back out side the kitchen even though he was seen being shot and falling within the kitchen.
At the end of the Wyndham Teahouse shoot out, Tequila (Chow Yun Fat), covered in flour, executes the mysterious gunman in the kitchen at point blank range with a single shot of his pistol. However, the slide of the semi-automatic pistol does not blow backwards to cycle the next round after Tequila pulls the trigger. In reality, this would indicate that the pistol would have failed to fire. It is possible that they had the actor fire an empty gun, or a non-firing prop gun, for safety purposes.