Continuity mistake: In the scene where 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.
Plot hole: In the scene where the FBI plays the tape to Tony and reveals the conspiracy between his mother and Junior, it is stated that the bugs were placed at Green Grove. However, the second conversation played in the sequence actually took place outside a movie theater the episode prior, which would not have been recorded as part of the Green Grove surveillance. The conversation involves Livia telling Junior that Tony reminded her of her cousin Kiki after she had her lobotomy.
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.
Continuity mistake: When Paulie Walnuts is talking to Tony in the hospital room, the close up of the heart monitor shows the heart rate in highlighted text, with the word "Tachycardia" flashing. In the shot from Paulie's point of view, the heart rate is in normal text and "Tachycardia" is not flashing.