Continuity mistake: During the scene when Bobby's auditioning for a part, there's a picture on the wall of Helen Martin (the lady playing Bobby's Grandma). The picture disappears and reappears during the scene.
Continuity mistake: When Frances takes Helen to sleep in the car, he puts her in the back seat from the drivers side. In the morning the camera is looking at her through the the window of the door on which she appears to be leaning. Yet when she gets out of the car later in the scene, there is a canvas draped over the door way.
Continuity mistake: When the pirates swears the oath to kill Dragon Mao, they drip blood on one of the pirate's hand. The blood stains on his hand differ between the shots. (00:02:50)
Continuity mistake: After the grocery store visit, Joan Jett walks to her room at the hotel and goes to her room on the second floor, a short time later she opens her room door which is now on the first floor. (01:35:00)