Factual error: When Beeks is locked in the cage with the gorilla, it reacts in an overtly aggressive and sexual manner. First, gorillas are shy and gentle creatures. The male gorilla would be scared of him, not the other way around. Second, gorillas identify each other by their smell, and the smell of a female in heat is very specific. Beeks would smell like a horsehair rug and the male gorilla wouldn't be the slightest bit interested.
Visible crew/equipment: When Winthorpe enters the Duke and Duke building he removes his coat and scarf, then as he walks toward his office the actor's two black tape marks (one where he stood, and one where the first woman said good morning) are visible on the floor behind him. (00:05:30)Super Grover
Other mistake: When the $50k check is revealed about Clarence Beeks, both Mortimer and Randolf's positions and their angles appear as if Winthrop is behind them, not in front. (00:15:00 - 00:17:00)
Continuity mistake: When Eddie Murphy and Dan Aykroyd's vehicles pull up next to each other in traffic, Eddie's window as seen from the outside is fully open, with a small closed side window. When we cut inside Eddie's limo, the full window is completely closed and there's no side window at all. It's a completely different limo.
Visible crew/equipment: As Murphy and Aykroyd are leaving the bathroom to head to the trading floor, you can see the shadow of the dolly track on the lower right hand side of the frame. For a brief second you can also see the actual dolly track before they enter onto the trading floor. (01:42:40)wkotansky