Continuity mistake: In the scene where Randy is playing table tennis on the stage at the restaurant, just after he has finished hitting the ball blindfolded and says, "Thank you", you can see a man in the background getting up. The shot then switches to the boy with the man in the background still sitting. The shot then switches back to Randy and the man is getting up again.
Deliberate mistake: When Randy is playing with Agent Rodriguez's gun (after first meeting him), when he accidentally fires it, you can tell the film inexplicably cuts forward a few frames into the same shot, as Randy's body suddenly shifts position and the gun is facing upwards, rather than at an angle as it was the frame before.
Other mistake: In one shot, a man is leaning over Feng and speaking in Chinese to him. The woman sitting next to Feng translates and says that it means the man has to go to the bathroom. Feng explains where it is and sits down. After, it switches shots to show the man leaving Feng's "throne" in the backround and sitting down, not going to the bathroom.