Continuity mistake: After Wes was clobbered and on the floor, he had a long stream of water/mucus coming out of his nose or mouth and his lips were wet when he was standing up, but his lips/mouth/nose were totally dry when the killer put his gloved hand over Wes' right shoulder. (00:33:40)
Other mistake: In the scene with a leak in the kitchen, the woman fixes it by turning an isolating tap above the leak. However the water would have been travelling up the pipe to the kitchen tap and so that wouldn't have stopped the leak. (00:34:00)
Character mistake: Jean rolls, kneads, and flattens the dough a few times, repeating the steps to give the image of still preparing the dough. After the dough was flattened, it was well-shaped (round, higher, and more compact) then flat again. The way she was shaping the dough suggests she was making biscuits, but biscuit dough should not be handled that much (or the biscuits would be flat and not flaky). (00:18:00 - 00:19:00)
Continuity mistake: Take notice of the desk lamp as Charlie and Al are talking in Charlie's new office. As the camera switches back and forth between their face to face conversation, the green glass cover of the light keeps changing position too. This happens even after Al leaves. This was probably done to keep the light out of the camera during filming. (00:13:50)
Deliberate mistake: Zhang crushed and smeared several long red-hot peppers (cayenne?) in his hands to use as a makeshift weapon against thugs when rescuing Mei Mei. After Zhang smeared and pushed peppers into one thug's eyes, it is unlikely he would have been able to retain as much of the crushed peppers in his palms as he did. Also, holding the peppers in one or both of his palms would have interfered with grasping the second thug and redirecting his gun (without sliding off). (00:08:00 - 00:08:50)
Factual error: Rich told Jamie, "There was a car accident. Guy came in. I cut when I should've stitched or stitched when I should've cut. I don't even know. His family sued in civil court, and I lost everything." A doctor working at a hospital would have been required to carry malpractice insurance, which would have protected him from "losing everything." Also, it would be difficult to prove that a car accident victim who died during surgery was a victim of malpractice; most cases are settled out of court. (00:38:30)