Continuity mistake: When the airline pilot enters first class to announce the baggage search, we see only 7 seated passengers and many empty seats. When the angle reverses, there are instantly 15 people seated, and almost no empty places.
Continuity mistake: When Mundy and Claire are sitting in the car outside the apartment building, the rear view mirror has disappeared (probably removed to prevent it from obscuring the actors' faces). It mysteriously reappears later on.
Continuity mistake: While he hangs from the ceiling over the jewels, Al's trapeze is spinning slowly. But when the shot cuts to a close-up, you can tell from the stationary background that the trapeze is now perfectly still. In the next full shot, though, it's spinning again.
Revealing mistake: Lori Chan picks Mundy up at the airport and proceeds to speed through town, spinning the steering wheel left, right and left again repeatedly. But the rear-screen projection behind them is showing footage from a car moving steadily in a straight line.
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.