Continuity mistake: When Dee is standing up she is smoking a cigarette with her right hand. When the shot comes back to her as she cuts Charlie's joke off, the cigarette has disappeared and the bottle of whiskey has left the table and is in her right hand.
Continuity mistake: When the gang barges into Dee's apartment they leave the door wide open. When the shot goes to Charlie and Dennis the door is half-way closed, when the shot goes back out to all 4 of them asking "Which one?" the door is open all the way again. It goes back to the Charlie and Dennis shot with the door halfway closed one more time before the scene closes.