Revealing mistake: Near the end when Ace gets into his Cadillac, in the first shot facing the front of the car, there is a protective glass in front of Ace (the same width as the windshield) with the dashboard in between that glass and the windshield. Note the vertical edge of the glass is visible at the right side, and the rearview mirror's sticker on the windshield casts a shadow onto the second glass. During the stunt, the flames on the dashboard are between the glass shield and the windshield, keeping the actor safe from harm. (02:46:05)
Revealing mistake: At the beginning of the film where Robert De Niro gets into his car and it explodes, you can clearly see the cut where they have replaced him with a dummy. (00:00:50)
Revealing mistake: When Sharon Stone gets thrown out of Joe Pesci's club, you can see the pads on Stone's hands to break the impact of the fall.
Revealing mistake: In the scene where Joe Pesci is beaten in the corn fields, if you look closely at the bats you will see them bend ridiculously on impact with his body. Foam bats anyone?
Visible crew/equipment: When Robert De Niro goes to meet Joe Pesci in the desert, the whole crew is reflected on the side of the car.
Continuity mistake: When Joe Pesci is beaten and then buried - look at the blood on his chest. In one shot it is all over - the next it is just a smaller patch.
Continuity mistake: When Remo Gaggi is talking to Andy Stone about Ace cussing out the Board, there's a pack of cigarettes beside Gaggi in his car. The camera angle changes to show Stone's face, who is outside the car, and when it flips back to Gaggi, there is a Zippo lighter in place of the cigarettes. The camera goes back to Stone, and when it comes back again, the Zippo is gone and the cigarettes are back. And to top it all off, not once did Remo smoke in this scene.
Continuity mistake: When Joe Pesci is stabbing the guy with a pen that insulted Ace, the pen is shown without blood after there was significant blood on it the cut before, then it goes back to having blood on it.
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.
Continuity mistake: When Joe Pesci and his brother are beaten and then buried, you see one bat and then suddenly, appearing from nowhere, three bats. Sometimes they are blood covered, then clean, then blood covered again. (02:47:30 - 02:48:25)
Continuity mistake: After meeting with Ginger about Lester being beaten up, Nicky is about to leave. Before he does, Ginger hugs him and puts her arms around his neck. In the next shot her right arm has suddenly moved and her elbow is now bent. (01:19:50)
Continuity mistake: In the scene where Sharon Stone is talking to Joe Pesci about how De Niro had his guys beat up James Woods, there are 4 security monitors on the desk behind Sharon Stone. First, the top left monitor goes out. Next only the bottom right monitor is on. Then all four monitors are off. Finally, all four monitors are on again. (01:18:05 - 01:19:20)
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.
Chosen answer: In the end.