Factual error: Unless Henry was intoxicated or heavily medicated during his sleep, it would have been impossible for Karen to have climbed on top of him in bed, point a gun at his head, without him ever feeling her body on top of his.
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.
Factual error: Early in the film, when Henry Hill is selling Pall Mall cigarettes out of a car trunk and is arrested, there are UPC price codes visible on the cartons of cigarettes. UPC codes were not used on products in the 1950's when the scene is taking place. They were introduced in the mid 1970s. (00:13:20)
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.
Factual error: The title of the scene says "Idlewild Airport 1963" but they are leaning against the trunk of a 1965 Chevrolet.
Factual error: When Henry and Karen are racing to Karen's mother's house when the helicopter is following them, the driveway Henry pulls up in has a 1982 or newer Pontiac Bonneville, but the scene was supposed to take place in 1980.
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)