Continuity mistake: In the beginning, as Nielsen plays his violin you can see a quiver on his back, the next scene it is gone.
Other mistake: Mr. Nielsen is hard of hearing and typically wears hearing aids during rehearsals, removing them for the actual takes. In the scene where he is eating spaghetti in the hotel room and watching the news on TV, he suddenly glances behind him at the initials written on the wall. When he turns his head, you can see the hearing aid in one ear; apparently he forgot to take it out before filming.
Continuity mistake: When Ryan jumps out of the back of the diaper truck, his face is completely normal. When he stands up, his face is blue and his cheeks have bulged out. (00:50:35)
Continuity mistake: In the beginning, in the concert scene, where Harrison does the Jimi Hendrix-style ending, he smashes his violin to pieces and the bow disappears somewhere. However, in the next shot, the violin and the bow are in his hand, intact.
Continuity mistake: When Harrison is trying to escape the hospital he takes a pair of glass stickers and sticks them to a metal plate on the wall. First time you see them they are almost besides each other but in the next shot he suddenly gets his legs between the stickers.
Continuity mistake: When the lady cop gets in the car, just after Harrison has hotwired the car and is driving off, the older, guy cop pushes a little vacant switch down. In the next scene, where you look through the windscreen, the switch is back up again.