Continuity mistake: When Janice is trying on her wedding gown with Carmela, her tattoo is gone. However, in all the other shots, her tattoo is above her cleavage line, between her boobs. It's nowhere to be seen in the wedding dress shots.
Revealing mistake: When the shrink locks the door on Tony, they argue and she calls the police. When she finally calms down she approaches the door to unlock it but you can see the door move before she ever sticks a key in it or touches the knob. (00:25:20)
Continuity mistake: Tony, Carmela and AJ are meeting with AJ's college tutor. Partway through the meeting AJ is asked to leave. When AJ stands up he is wearing beige coloured trousers, but as the shot changes to show him walking out the door, he is now wearing black trousers. (00:15:30)
Continuity mistake: In the scene where Bacala is telling Uncle Jun about his father and the accident, Uncle Junior gets angry and starts throwing things around, he is wearing glasses. You can see that in between throwing one of the items, he is not wearing his glasses, then he is wearing them again.
Factual error: During Tony's assassination attempt he struggles with one of the "hit men" for control of a pistol. One can see that the pistol does not contain a magazine.This would limit the shooter to 1 shot, providing the pistol is not equipped with a "magazine disconnect" if it is than it can not be fired at all. It seems unlikely that a "hit man" would be so ill prepared.
Character mistake: When Tony tells Dr. Melfi he feels as though a safe might fall on his head, she replies, "a feeling of pending doom." A woman of her intellect and education should know the proper word is "impending." "Pending" means something awaiting a conclusion. "Impending" means about to occur.