In the establishing shots of "Idlewild Airport, 1963,"a Swissair jet's livery has black and dark green stripes and the title "Swissair" in lower-case red letters on the fuselage. That color scheme was introduced in 1981.
Near the end, when Henry is driving around watching for the helicopter, a package of Winston cigarettes is on the dashboard of his car. The scene is set in 1980, but the package design was introduced in 1987.
The pay phone in the airport diner is of the familiar current design, which was introduced by the Bell System in the late 1960s, or several years after this scene takes place (1963). It is, however, the rotary dial version.
In a segment introduced as Brooklyn, 1955, the camera follows Henry running off to his job at the cab stand. Part of the view is a look through the utility poles to show the surrounding neighborhood. The shot includes a modern cable television amplifier.
When Henry is almost in an accident, the door of a Nassau County Police patrol car appears for a split second. The emblem on the door is the Nassau Police shoulder patch, which they did not display on their cars until the mid-1980's, not in May 1980 when the scene was set.
When Henry takes Karen to the Copa, they enter through a service door and through a labyrinth of passageways until they finally emerge in the dining room. As the camera follows them on their journey, a modern fire extinguisher is near the kitchen area. At the time, most fire extinguishers were either the dry powder, push-handle type (similar to old insect sprays) or gravity-fed liquid extinguishers that worked by turning the unit upside down and directing the nozzle. The extinguisher in the scene is a modern pressurized CO2 extinguisher with an OSHA filling inspection tag attached, which wasn't required in the early to mid 1960s.
When Johnny and the boys are making spaghetti in the late 1950s, a bottle of dish soap in the window sill has a UPC bar code. The bar code was first tried in 1966, became a new industry standard in 1970, and was first scanned in 1974.
When Henry and Karen are on their date at the Copa, they are drinking champagne from large flute glasses. While a 4oz flute that had been introduced in the 1930s, Henry and Karen should have been drinking from coupe style glasses as large flutes did not become popular until the mid-seventies.
In the footnotes, it is noted that "In 1989, Henry and Karen Hill separated after 25 years of marriage", and yet the Corvette parked over the road from Karen's mother's house (before their marriage) is a 1966 model.
In an early scene, the narrator says, "It was before Apalachin," referring to the upstate New York town where a late-1950s Mafia summit was raided by police, making national headlines. He pronounces it "ap-a-LAY-chin," instead of "ap-a-LAY-kin."
When Sonny Bunz has his sit-down with Paulie about Tommy, an over-the-shoulder shot from behind Sonny shows Paulie talking with a cigar in his mouth. In the next shot, an over-the-shoulder shot of Sonny, Paulie's cigar is gone. In the following shot, another over-the-shoulder from behind Sonny, Paulie has the cigar in his mouth again.
When the police car pulls up while Jimmy is handing out cartons of cigarettes from the truck heist, the same two-tone brown 1957 Buick two-door sedan drives by several times, in the same direction, in the background.
When Henry brings in the bag of supplies in jail, he hands the wine bottles to Paulie, then picks up a bottle of scotch and two jars. In the next shot, he is holding bread, a different bottle of scotch, and two jars.
On May 11, 1980, when Henry and Karen are at the shopping center, they leave their car by the curb in front of the store. When they leave the store later, after looking out for the helicopters, the car is parked in the parking lot.
Just before Henry enters the jail cell with a bag of supplies, Paulie sits at the table drinking. A jar containing a bunch of fresh basil is in the middle of the table. Paulie is still drinking in the next shot, but the jar and the basil are gone.
Henry looks into a bag filled with $20 bills. They're signed by "James A. Baker" (James Baker III), who was Treasury Secretary in 1985. The scene is set in the mid to late 1970s. Also, the money is clearly photocopies and not genuine currency.
When Maury's address is shown in his TV ad, not only is the number not hyphenated (as all Queens addresses are) are, but address should be "Neighborhood, NY", not "Queens, NY". Except for Manhattan, which is always "New York, NY", the names of the other New York boroughs are used in addresses.
In the 1955 sequences, Tommy DeVito is portrayed as a boy about the same age as Henry Hill, maybe slightly older. Pesci's character was based on real-life mobster who was born in 1950. He would have been 4 or 5 years old when these events took place.
When Henry picks up his brother at the hospital after nearly being in an accident, the doctor gives him an orange tablet which is suppose to Valium 10mg but Valium 10mg tablets are blue. Valium 5mg tablets are yellow; therefore, it could not have been two 5mg tablets.
When the mailman's head is pushed into the pizza oven, his hand is clearly seen resting on the inside of the oven door before the image is frozen, even though a cooked pizza is shown inside the oven as it is opened (i.e. it was too hot for him to keep his hand there for the few seconds shown without reacting).
At the airport, when Tommy and Henry take the Sargent key and walk over to the locked storeroom, the whole knob turns when the key is turned. That means the lock was already unlocked. If it had been locked, only the key would've turned.
When Henry brings the guns for the silencers that have already been purchased, the silencers are threaded and the barrels are too big. In reality, gun barrels are threaded and the silencers fit over them.
In the legendary steadicam scene, Henry and Karen's route doubles back on itself in the kitchen. As they turn left to enter the kitchen, a fire hose is behind a waiter in front of them; Thirty seconds later, they emerge from the same door with the fire hose on their left. Henry doesn't take them through the kitchen at all, they just walk around inside it. They could have passed the kitchen door and turned right into the nightclub.
When Karen visits Henry in prison and she has to sign the register, she scans the entries in the book. With the camera looking at the register from Karen's point of view, Karen spots Henry's name, then her eyes look to the right to see who had visited him. The camera pans to the left, not the right.
When Henry hears about the Lufthansa heist on the radio while taking a shower, the radio is tuned to 710 AM. The station playing, identifiable by its signature "you give us 22 minutes" sounder, is AM 1010 WINS.
The goof items below may give away important plot points.
When Tommy kills Stacks, the silencer is heard three times after he shoots Stacks in the head. During the slow-motion replay, Tommy shoots Stacks 5 times in the back, 2 times more than in the previous scene.
When Jimmy opens up the trunk of the car and finds Billy Batts still alive, Tommy pulls out a large butcher knife and plunges it into Batts almost to the hilt several times. He then stands watching while Jimmy empties his gun into Batts' body. There is no blood on either Tommy's hands or the knife.
A title card dates the Billy Batts murder as June 11, 1970. When they go to dig up the grave, Henry says "it's been six months." It should be winter in New York, but the boys are in short sleeves and Henry's kids are going to the beach the next day.
Every scene coming to or going from Karen's home, regardless of passage of time, (i.e. the neighbor rough-up, Henry leaving) was obviously shot in the spring, with all trees, shrubs in the same state of bloom. In the latest shot, the hot pink almond or dogwood tree was faded.
When Tommy kills Stacks, Carbone stands in the doorway and watches Tommy shoot Stacks three more times after shooting him once in the head. In the slow motion alternate view, Carbone is not in the doorway, and Tommy shoots Stacks five more times instead of three.
When Tommy takes out Stacks, he says, "You'd be late to your own funeral" as he puts the gun to the back of Stacks' head. When they show Tommy in slow motion, he doesn't say anything. Tommy shoots him once in the head, then changes positions before shooting him again. In slow-mo, we don't see the first shot, only the latter ones.