The opening scene is supposed to take place in 1960, but both during the shots of the Manhattan skyline and their drive through New Jersey there are many buildings visible that were not constructed until years later.
At around 26 minutes there is a Exxon sign in the get away scene. Esso didn't become Exxon until 1972 the movie supposedly is taken place in 1960?
When Falco is in the iron lung addressing his retinue, it would be impossible to continuously speak because the machine forces the patient to inhale and exhale in a rhythmic manner.
In the scene where an artist is using a bridge as the subject of his painting, what he's painting doesn't match the view he has of the bridge. The span of the bridge in the painting goes in the opposite direction of the actual bridge.
When the movie starts, the date is Sept. 15, 1960. The men are riding in a car. They begin to sing along with an opera that is playing on the radio. The car arrives at its destination, a charcoal grill. When they exit the car it is plain to see that the car hasn't even been built yet. It is a 1963 Cadillac Coupe DeVille.
A Honda dealership is seen when in it wasn't until 1969 that Honda Automobiles were sold in the United States.
The cans of Schaffer Beer are the current 1974 design and not the proper 1960's design.
Many post 1960 automobiles are in the film.
Not totally sure about this...but around minute 3 into the film (set in 1960) Joe and buddies are driving over a bridge. We are shown several views of NYC from this bridge...in one shot, I believe we see the Twin Towers in the background. If I'm right, this would not be possible since the Twin Towers were being built/completed in the early 1970s.
The setting of the film is 1960 but most of the men's hairstyles, facial hair, and automobiles are present day (1974).