Continuity mistake: In the final scenes at the airport, when Rick is talking to Major Strasser, the epaulettes on Strasser's shoulders alternately appear and disappear.
Continuity mistake: When Bogie is reading the note from Bergman, it is dissolved by the heavy rain and he is dripping wet, so is Sam, who delivered the note. But then he is standing on the step of the train totally dry.
Continuity mistake: When Rick goes to see Ferrari at the Blue Parrot the first time, there is a bottle on the table between them. Ferrari is shown taking the cap off the bottle, pouring a drink, and then returning the cap to the bottle. In the next cut, the bottle is gone, and in the cut after that the bottle is back, but without the cap, which should still be on it.
Rick: I'm saying it because it's true. Inside of us, we both know you belong with Victor. You're part of his work, the thing that keeps him going. If that plane leaves the ground and you're not with him, you'll regret it. Maybe not today. Maybe not tomorrow, but soon and for the rest of your life.
Ilsa: But what about us?
Rick: We'll always have Paris. We didn't have, we, we lost it until you came to Casablanca. We got it back last night.
Ilsa: When I said I would never leave you.
Rick: And you never will. But I've got a job to do, too. Where I'm going, you can't follow. What I've got to do, you can't be any part of. Ilsa, I'm no good at being noble, but it doesn't take much to see that the problems of three little people don't amount to a hill of beans in this crazy world. Someday you'll understand that. Now, now... Here's looking at you kid.
Ilsa: Play it once, Sam. For old times' sake.
Sam: [lying.] I don't know what you mean, Miss Elsa.
Ilsa: Play it, Sam. Play "As Time Goes By."
Sam: [lying.] Oh, I can't remember it, Miss Elsa. I'm a little rusty on it.
Ilsa: I'll hum it for you. Da.dee.da.dee.da.dum, da.dee.da.dee.da.dum...
[Sam begins playing on the piano.]
Ilsa: Sing it, Sam.
Sam: [singing.] You must remember this / A kiss is still a kiss / A sigh is just a sigh / The fundamental things apply / As time goes by. / And when two lovers woo, / They still say, "I love you" / On that you can rely / No matter what the future brings...
Rick: [rushing up.] Sam, I thought I told you never to play...
[Rick sees Ilsa. Sam closes the piano and rolls it away.].