Revealing mistake: During the sax player's solo (final concert), his fingers don't match the notes, and he stops moving his fingers before the solo is over. Also, the sax player in the blue jacket behind Buddy's right side often lags behind the sax player to his right. At times, it looked like the sax player was watching the sax player next to him to know when to play. Sometimes, he would put the reed in his mouth for a fraction of a section and just pretend to be playing. Near the end, both sax players seem lost and even laughing at themselves. (01:47:17)
Revealing mistake: Watch carefully during the fight scene between Billy and Rifki, you can see the stuntmen a few times.