Factual error: In one scene a parked car is sitting along the street - it is a '68 Chevy, it has sidelights. Yet the film is set in 1962.
Factual error: On the night of 19 October 1933 the railroad workers begin betting whether A-One will make it to Portland on the 19. A quick closeup of the money changing hands reveals the $1's to have the Great Seal reverse (introduced in 1935) plus the motto IN GOD WE TRUST (introduced in 1957). Also, the green-seal Federal Reserve Notes and the red-seal United States $2 notes are of the types first introduced in 1934.
Factual error: Near the end of the chase, when Buddy is ramming the bad guys' car, the scene is supposed to take place in New Jersey as they just crossed the George Washington Bridge. However we see a road sign for NY 100/133, indicating they are back in New York state on the Taconic State Parkway.
Factual error: While Sgt Howie (dressed as Punch) is being chased by the women, you can see autumn leaves on the grass, though the story is set on the 1st of May.
Factual error: When Clint Eastwood first goes to the barber shop, the barber very deliberately sharpens his razor the wrong way, flipping the blade with its sharp edge against the strop - this would instantly dull the blade. No real barber would make this mistake, but it's a common movie error.
Factual error: Buford drives into his yard on Christmas morning and there are green leaves on the trees. Not in Tennessee, in winter!
Factual error: The records played in the fairground sequence "Sealed with a kiss" by Brian Hyland and "Runaway" by Del Shannon date from the early sixties, while this part of the film is set in 1959.
Factual error: Many shots, especially the early ones, include the iconic Renault 16 in the background. This car was first produced in c1965, three years after the events happened. Probably unavoidable, as the car was a huge success.
Factual error: The kid is wearing a Texas Rangers baseball cap. The Rangers didn't come to Texas until 1972.
Factual error: The skywriting at the end of the film would have long drifted away by the time it is shown. The pilot has since landed on the road, taken off again and Jack & Ruby have made up, yet it is still in perfect formation.
Factual error: During the flashback explaining what happened to Su Lin she has an ugly bruise on her face less than a minute after being hit. Bruises usually take at least a few hours to develop like that.
Factual error: James Caan plays a US Navy Boatswain (Bo'sun) Mate. His rank insignia of BM 1st Class should be worn on the right sleeve, but he has it on the left.
Factual error: When the pimp murders the hooker in the taxi, he is said to have forced drain cleaner down her throat. However, he uses an aerosol can. You can even hear the metal ball shaking inside of it several times. In the 1970s, drain cleaner did come in metal cans, but what he is using is a spray can of some kind, which drain cleaner did not come in. It is always in liquid form to pour down a drain, spray would not release enough.
Factual error: The document Shaft checks out when he kills the bus assassin is not a passport, but a driving license. It's also missing the signature, and the name of the city (Sardinia's capital city) is misspelled as Caliari instead of Cagliari; even worse, a scribbled line where the issue date should be. An official document like it's supposed to be generally had all the information typed and not handwritten, but if it were handwritten, it needed to be in block letters, not the way it is in the movie, in longhand and with such awful penmanship. (00:40:35)
Factual error: The oil "drill" is actually an oil rig, meant to pump oil, not drill for it.
Factual error: In the second chase scene (when Gator is blocking for Roy) it shows Gator turning on to Laurel street then entering into the parking lot and the storage area of a lumberyard (where the lumber falls on the state police car). Laurel St. is in N. Little Rock and the lumberyard is the old Wrape Stave lumber yard (also known as Dixie Culvert) in E. Sixth street in Little Rock.