Other mistake: In the scene after De Niro's car explodes, they show him being put in the ambulance feet first. Patients are always put in head first.
Continuity mistake: When Ace fires Don Ward, the shot is on Ace and you can see Don turn away. When the shot changes to Don, you see him turn away again.
Factual error: In the jewelry robbery montage, Joe Pesci is shown holding a rechargeable Mag-Lite flashlight which would not have been available at that time.
Continuity mistake: When Robert De Niro is at the restaurant with Sharon Stone and catches her with James Woods, the menu under his hands goes from being horizontal to vertical.
Continuity mistake: When Artie Viscano is complaining to his brother in law about Las Vegas, he backs into about 10 bottles. They all fall except for two, and then the scene cuts to to his brother in law and when the scene cuts back to Viscano, all the bottles are back up.
Visible crew/equipment: In the scene where DeNiro is throwing Sharon Stone's character out of the house after overhearing her on the telephone, he drags her into the bedroom. Just before the scene cuts away, the camera appears in the mirror on the wall behind them.
Revealing mistake: In the scene where Pesci's character is being buried alive, the body is quite obviously a fake: look at the mechanical way the head moves, and the movement of the chest intended to simulate breathing, not very convincingly.
Revealing mistake: When Nance comes stumbling out of the Costa Rican house holding his stomach, you can tell he is holding a mouth full of blood that he spits out when he gets shot in the head.
Audio problem: In the scene where Sharon Stone is talking to Joe Pesci about how De Niro had his guys beat up James Woods, at one point Sharon Stone says, "Oh C'mon." If you look closely her mouth doesn't move at all. Also if you listen closely, that line comes out on surround sound. When she continues her line it comes out on mono. It was obviously recorded.
Factual error: When Ace is watching the news report about the investigation of his gaming license and crime connections, you can see the Mirage Hotel in the background of the news studio. The Mirage was not opened until late 1989, and the movie takes place well before that.
Continuity mistake: When DeNiro catches the cheats at the card tables, he takes the one with the beard to smash his hand with a hammer. In the first shot the guard is holding the cheat down by the wrist, but in the next shot the guard's hand is up by the guy's elbow.
Factual error: When Joe Pesci is driving to meet De Niro, he has to change cars. The scene right before going to the garage, they show Pesci's car driving around a corner and at the bottom right of the screen, you see a lamp post with a bus sign on it that reads CAT. CAT (Citizen's Area Transit) wasn't established in Las Vegas until late 80's early 90's. Before that it was the Las Vegas Transit. This scene was supposed to be late 70's, early 80's...
Continuity mistake: When De Niro catches Stone and Woods in the restaurant, De Niro takes out some money from his coat pocket and lays it on the table. In one shot the money is straight, in another it is diagonal and in the final shot before De Niro picks it up it is straight again.
Continuity mistake: When Ginger is arguing with the gambler at the craps table about "giving her a bigger cut", the man reaches for her purse to show her the chips she's been stealing from him. As she pulls the purse back, the gold chain strap breaks. The next shot of Ginger shows a repaired chain.
Audio problem: Ace yells "come with me now" over and over while dragging Ginger out of the house after overhearing her trying to have him whacked. DeNiro's lips are not moving while he's yelling.
Continuity mistake: Jennifer has the diamonds inside her hair bun and she's shaking it to retrieve the diamonds onto the table. As Santoro slaps her face as a gesture to thank her and for her not to get smart with him, her hair bun comes loose and falls out into a pony tail. The next shot then shows Jennifer with the hair bun perfectly groomed again on top of her head.
Continuity mistake: When Nicky has the guy's head in a vise, after it squirts Nicky's hair changes between shots, from neat to messed up.
Continuity mistake: Towards the end of the movie, when they first kill Nicky's brother, Dominick, and they throw him in the pit, his full chest is covered in blood, but in the aerial shot it is clean with just the bloody face.
Visible crew/equipment: When Ginger obtains the deposit box's key after having rushed to Ace's house and goes to the bank to open the deposit box, a boom mic can be seen reflected on the bank's glass door.
Continuity mistake: Before Pesci stabs the pen, DeNiro asks a guy if it's his pen. A glass on the right, inches away from the napkin where the pen was laying, appears and disappears between shots.
Answer: Frank Rosenthal (the basis for Sam Rothstein) and Tony Spilotro (the basis for Nicky Santoro) were both from Chicago, so that is likely "back home".