Visible crew/equipment: As Spade gives the guns back to Wilmer Cook in Kasper Gutman's hotel room an equipment shadow appears on Cook as they proceed to the couch. (00:57:45)
Continuity mistake: At Spade's apartment, Brigid O'Shaughnessy and Joel Cairo get into a fight just as Detectives Dundy and Polhaus are talking to him at the front door. They come in and Joel has blood on his face, but it changes between shots throughout the scene. (00:39:10)
Continuity mistake: Spade goes up to Kasper Gutman's hotel room, gets mad and storms out. Before he leaves, everything on the liquor tray on the table in front of them moves between shots. (00:54:25)
Continuity mistake: Joel Cairo walks into Spade's office and his phone is on some papers in some shots and not in others. (00:23:35)
Continuity mistake: Kasper Gutman says, "Come come, Mr. Spade. You can't expect us to believe at this late date that you're the least bit afraid of the police" with his left hand on his chin. In the next shot his left hand is at his side. (01:14:05)
Continuity mistake: In his hotel room as they speak about the black bird, Kasper Gutman pours Spade a drink. A second glass appears on the table just before they sit down. (00:58:10)
Visible crew/equipment: When detective Dundy visits Spade in the middle of the night and asks, "What kind of gun do you carry?" an equipment shadow can be seen moving above Spade's head on the lamp. (00:11:10)
Continuity mistake: As Sam Spade slaps Joel Cairo, Joe's bow-tie changes from polka dots to stripes.
Continuity mistake: Miles Archer walks in and throws his hat on his desk as Sam Spade speaks to Brigid O'Shaughnessy in the first scene of the movie. The hat is leaning against a letter holder on Miles' desk, later it's in the letter holder and no one went near it. (00:05:45)
Continuity mistake: Capt. Jacobi brings the Maltese Falcon to Spade's office and drops it at his feet. The Falcon is tied up with string with the center having one strand wrapped around it. Later when Spade picks it up the center has two strands of string tied together around it. (00:07:00)
Factual error: In the opening credits, it says that the Knights Templar of Malta paid tribute to the King of Spain with the Falcon in 1539. The Knights that were in Malta were the Knights Hospitallers of the Order of St. John of Jerusalem. They mixed with the order of the Knights Templar, which went out of existence in 1314 and has also been founded in Jerusalem. They had nothing to do with Malta.
