Character mistake: When Spade leaves Brigid in her hotel room, he says he will buzz her buzzer long-short-long-short, so she will know it's him. When he does return, he only buzzes long-short.
The Maltese Falcon (1941)
1 character mistake - chronological order
Directed by: John Huston
Starring: Humphrey Bogart, Peter Lorre, Mary Astor, Gladys George
Continuity mistake: After going through his pockets, Spade holds Joel Cairo's three passports in his hand, but if you watch closely he puts four passports onto the top of the table. (00:25:50)
Tom: What is the Maltese Falcon made of, to make it so special?
Spade: The stuff that dreams are made of.