Continuity mistake: Stuart Sutcliffe talks in a Liverpool accent throughout the film. However, unlike the other Beatles, Sutcliffe didn't have a Liverpool accent. He was born in Scotland and raised in Lancaster. He didn't come to Liverpool until he was 16.
Continuity mistake: At the wrap party for "Bride of the Atom," when Dolores starts screaming at Ed "These movies are TERRIBLE!" her hair is curled in ringlets that hang down to the tops of her shoulders. She then stalks out of the warehouse, and Ed follows her. When he catches up to her in the parking lot, and she tells him she is leaving him, you can clearly see that her hair is suddenly much shorter and curlier.
Continuity mistake: When Morgan is shot while playing pool he is placed on the pool table. An overhead shot shows a wide pool of blood spreading from his right side. In a subsequent shot the pool of blood is much narrower and a completely different shape.
Continuity mistake: In the scene where Lane, Tuff and Cody are talking about Leffow right before Lane rides there is no leather strip around Lane's neck to tie his glove on with. In the next shot he has the leather strip around his neck. (00:28:35)
Continuity mistake: After Beethoven pulls his nephew out of the tavern and yells that he is worthless, Beethoven is seen doubling over in pain. When the shot cuts to Karl, Beethoven is in the background, standing up straight, and doubles over again.