Factual error: Gino commits a murder using a six-shooter with a silencer attached, and his shot doesn't make any noise. But it should have. Though it's a long-standing Hollywood cliché, a revolver with a silencer wouldn't be silent at all. Unlike automatic weapons, revolvers are open-chambered, which allows sound to escape. They can't be muffled with a silencer.
Continuity mistake: The professor translates the two Chinese symbols from Mundy's brass rubbing. Then he's shown a Chinese business card, and states that the 12 symbols on the card say the same thing. But not one of the symbols on the card matches the first two from the paper.
Plot hole: While Mundy is trying to disarm the briefcase bomb in the study, his time-sensitive work is interrupted no less than 6 times by people barging in from the party out front. The plot device adds comic relief, but there's no earthly reason why he couldn't have locked or barricaded the door in the first place.