Continuity mistake: Henry and Jimmy are eating in a diner waiting for word about Tommy being "made". When Jimmy goes outside to make the call to find out, there is a car parked outside the diner, at this point, the car's window is open. When Jimmy starts kicking over the phonebooth and Henry comes outside to join him, the car's window is closed. (01:51:35)
Continuity mistake: When Henry has just shown De Niro the guns and he returns to his car, you see him light up a cigarette. When the shot changes the cigarette has vanished. (01:54:45)
Visible crew/equipment: When Henry takes a look outside to see if the helicopter is circling, a boom mic is reflected on the glass door. (01:57:00)
Continuity mistake: In the scene that Karen is too afraid to take the clothes and the license plate falls off, there is a shot of the windshield which is close enough to reveal the fake registration sticker made for the era in which the movie was represented. The problem is though that not only is it obvious that the sticker is applied on the outside of the window, but the current sticker (inside the window) is larger than the movie prop and can be seen as a "frame" around the other. (02:11:30)
Revealing mistake: In the scene where Karen is too afraid to accept free clothes from Jimmy and speeds off, the yellow NY state license plate falls from the parked car to reveal the modern white one underneath. (02:11:35)
Factual error: When Henry meets with Jimmy after his arrest, the scene takes place in 1980, yet a 1984 or newer white Corvette is seen parked across the street at the end of the scene. (02:14:50)
Other mistake: Billy Batts is killed and buried in June 1970. Later on, Jimmy tells Henry that they have to dig the remains up due to condos being built on the site; Henry says "that was 6 months ago", putting the time frame at December 1970. In the car trunk-cleaning scene that follows, the trees are in full green foliage and Henry is dressed for summer. (02:36:00)
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.
Factual error: In the scene at Idlewild airport, the actors walk past the rear of an easily identified 1965 Chevy Impala. Occasionally Chevrolet introduced vehicles early, but never two years early.
Factual error: In one scene we are introduced to Idlewild Airport in 1963. We're shown a couple of aircraft in flight and one of the aircraft is a Boeing 747 in the livery of KLM Royal Dutch Airlines. The Boeing 747 didn't enter commercial service until 1969. Additionally, one of the 747s shown is actually a 747 'SP' (for 'Specual Performance') a version of the Jumbo Jet with a shorter fuselage which did not enter service until the mid 1970s.
Audio problem: When Henry asks Karen who assaulted her, she says "this guy who lives across the street from me that I've known all my life", but when she turns to face toward the camera her lips moving don't match what she's saying.
Continuity mistake: It's the scene where Henry and Karen are visiting some friends and they have their children with them. Henry starts to greet his friends, he is then carrying a big brown teddybear in his hand. Then Paul starts talking to him about Billy for a while, when the camera then is behind them as they walk away Henry is holding a little pink teddybear and he had no opportunity to switch.
Continuity mistake: The scene in the restaurant where Joe Pesci messes with Ray Liotta saying, "What, am I funny, am I a funny guy to you?" watch the drinking glasses on the table. The drink levels are going up and down with and then without ice.
Factual error: In the scene where Henry pistol-whips Karen's neighbor, Henry is driving a 1966 Chrysler, when it 1964 at the latest. We know this because at the end of the movie it says that Henry and Karen were divorced in 1989 after 25 years of marriage. That means they were married in 1964.
Continuity mistake: When Tommy is having a go at Henry in the Copana bar about saying he's a funny guy, the shots from behind Tommy, Henry has his left elbow leaning on the table with a cigarette in his hand. In the reverse shots(behind Henry) his arm is down. This continues throughout the "How am I funny" speech.
Factual error: The title of the scene says "Idlewild Airport 1963" but they are leaning against the trunk of a 1965 Chevrolet.
Continuity mistake: In the scene after the 'robbery' of the suitcase of cash by Henry and Tommy, Pauly, Jimmy, Henry and Tommy are all celebrating their success, laughing etc. with the suitcase of cash on a table. While Pauly is telling Henry to tell anyone who asks that he won the money playing craps in Vegas, Jimmy is standing quite some distance to the left of Henry.When the camera closes in on Henry and Pauly, Jimmy has moved positions - he is now directly behind Henry's right shoulder (on the left of shot). This is obviously for effect so Jimmy can be seen laughing in the background.
Other mistake: In the scene where Jimmy and Henry try to strangle Maury with the telephone cord, the handset is off the hook, but the telephone still somehow rings.
Continuity mistake: When Henry is in prison, Karen comes to visit him and drop off goods she smuggled in. They begin to argue while Henry is holding his daughter and Karen starts placing all the goods on the table. The camera angle switches to just a view of Henry's hands gathering the goods and if you look carefully, you will notice that BOTH of Henry's hands are collecting the goods. This would be impossible considering he is holding his daughter in one of his arms. Once the goods are collected, Henry is seen holding his daughter again.
Continuity mistake: When Ray's girlfriend is showing off her apartment to her two girlfriends they walk down the hall to the bedroom. The camera then changes to them entering the bedroom door and the order of girls has changed.
