Continuity mistake: During the last scene, right before Louise takes off her necklace, Brad is seen dancing with his jacket on. Seconds later when we see him again he has his coat off and now he's on the side of the dance floor.
Continuity mistake: In the last scene, during Louise and Brad's kiss, there is a girl with very blonde hair wearing a black dress dancing next to Louise and Brad. The shot changes to a wider view and she's all the way on the other side of the dance floor now.
Continuity mistake: In the last scene, right after Louise throws her necklace to Madame Serena, you can see a guy behind her with a mullet. In the next shot, Brad is shown walking towards Louise and if you look in the background, you can see the same guy.