Other mistake: After the "fat fat fatty" scene, Franz shoots his way in, starting with three bullets into the door lock. Over the next scene he fires about twelve shots, despite the fact he's firing an 8-shot Luger.
Audio problem: During LSD's performance of "Love Power" at the Springtime for Hitler auditions, it's possible to hear musical instruments that the members of his band do not play, for example a bass guitar, drums, and a flute are heard but not seen.
Continuity mistake: In the scene where Max and Leo visit Roger DeBris, Karman Ghia instructs them to remove their shoes because of the white carpet, and they do so. In the next scene, Max and Leo sit down and you can clearly see they have their shoes on. (00:42:25)
Continuity mistake: In the scene in which Bloom first meets Bialystock, Bialystock throws his coffee on the dirty window and wipes it with his white scarf leaving a large dark wet spot in the middle of the scarf. A few minutes later the spot has disappeared. (00:12:25)
Continuity mistake: In the scene that introduces the gorgeous secretary Ulla, Bloom has a cigar in his mouth, after a cutaway shot the cigar disappears, then after a second cutaway the cigar reappears.
Audio problem: When LSD is at the piano during his first Springtime for Hitler scene, the piano is heard being played but mostly he just touches the the keys without actually playing them.
Continuity mistake: When Leo and Max are going up the tiny elevator with the assistant to see the director, they are side by side in the low shot. When they cut to an overhead shot they are belly to belly, then when we cut low again, they are back to being side by side.
Continuity mistake: When Max pours water on Leo in the first big scene, Leo's jacket is very wet in the close up scenes and almost completely dry in the wide shots.