Continuity mistake: Kasper Gutman drugs Spade and as they get up from the couch after speaking about the black bird we see a vase on table with roses in it. The roses have been rearranged and the items on top of the table have moved throughout the scene even though no one has gone near it. (01:03:20)????
Continuity mistake: Spade walks into his office and Effie tells him that Kasper Gutman called and that Brigid O'Shaughnessy is in his private office. When he first walks in there's nothing by the water cooler on their left but several shots later he walks out to talk to Effie again and now there's a coat rack with several coats on it moved up next to the water cooler. (00:47:25)????
Continuity mistake: Joel Cairo plays with his umbrella as he speaks to Spade about the possibility of him finding the Maltese Falcon. When he says, "I am prepared to pay, on behalf of the figure's rightful owner, the sum of $5,000 for its recovery," the handle of the umbrella changes positions between shots. (00:24:40)????