When Danny and John are eating at one point, John eats all the spaghetti from his fork, but he still has some spaghetti in his fork in the next shot.
As Stephenson and Kilmer share a bottle of whiskey in front of the trailer, the contents of the bottle seem to grow in some of the shots.
St. Malachi's Church in Cleveland is spelled with an 'i,' not a "y" as shown in the movie.
Many vintage cars are used in this film, most of them mint specimens that are clearly collectors' items. But the makers ignored the fact that Cleveland winters usually took a costly toll on vehicles driven year-round. One scene, in particular, shows Danny's wife leaving him in what appears to be a 1955 Ford. A 20-year-old car in Cleveland back in the '70 would have been rusted out dreadfully with holes in the fenders and rocker panels. This beauty looks like it left the showroom last week! Look closely at the cars in the film and you will see they are all in perfect condition even though they would have been five or 10 years old.
Shondor Birns was not killed standing next to his Lincoln Continental as depicted. Birns was blown to bits at 8 last night seconds after he entered his car parked behind a West Side bar. Birns was hurled through the roof of a 1975 light blue Lincoln Continental Mark IV. The upper torso was found beside the opened front passenger door.
They also said the explosives were placed under the front passenger seat.
In the opening credits scene, Progressive Field (home of the Cleveland Indians) can be seen in the background of the Cleveland skyline. However, the park opened in 1994, whereas Danny Greene died in 1977, a 17-year difference.
When Billy McComber is killed, the bomb is planted in the shipping container next to Billy's car, and the front of the shipping container is clearly blown off. But in the subsequent scene that shows the car falling through to the water, the front of the shipping container is intact.
In the opening scene Danny is driving his Cadillac just before the explosion and he and has a Hula Girl on the dash, this is a late model Hula and was made after 2000, the newer resin mold with the guitar.
Danny turns down a beer at his girlfriend's apartment and asks if she has a soda. In the '70s, nobody in Cleveland (or northeast Ohio) would even know what a soda was; they would have asked her for a pop. Even non-natives quickly adopted this term when referring to a soft drink; occasionally a soft drink might be called a coke but never a soda. The term soda referred to carbonated water used in a mixed drink.
Julius was actually killed from the backseat by Ray Ferritto in 1969 in an LA airport parking garage, several years before its portrayal in the movie. Ferritto used the sound of a jet passing overhead to mask the sound of the gun going off.
An intersection scene repeatedly shows a walk/don't walk sign that is the current red hand/white walking man; this couldn't have been around in the late 1970s.
When at the fruit market, Danny is holding a shopping basket. The basket is a present day basket, made of plastic. Baskets during the early 1970s would have been made of metal.
One of the first bar scenes has two men sitting at the bar with Pabst Blue Ribbon bottles. Both bottles have UPC bar codes on the labels. UPC labeling wasn't used until the 1980s and later.
Danny had an appointment with a dentist on Brainerd Road in Lyndhurst. Lyndhurst is a leafy suburb but the scene is set in a grimy downtown parking lot.
After getting out of jail, Danny makes a call from a wooden phone booth standing out on a corner. Phone booths of this type were only used indoors. Outside phone booths were aluminum.
The Irish whiskey the characters drink in the movie is Bushmill. No true Irishman would drink that whiskey as it's from Northern Ireland. Would have been more accurate to drink Jameson.