Revealing mistake: In the scene where Lorraine Bracco points a revolver at Ray Liotta's head, after Ray Liotta turns the tables and now points the gun at Lorraine Bracco as he gets up and walks away you can see Ray Liotta steps on Lorraine Bracco's hand and she opens her mouth wide like shes screaming but it must have been cut from the audio, as Ray walks off camera his expression changes to show that he knew he had accidentally stepped on his co-workers hand.
Revealing mistake: When the Krays are boxing for the first time, their mum comes in to break them up. She runs up to the ring where a member of the crowd holds the middle rope lower to help her get in the ring. The problem is, he pulls the rope before he sees her making her way to the ring. It can't be a coincidence as he lets go as soon as she's in the ring. (00:26:30)