Continuity mistake: In the first 1968 section, where Noodles rents a car and drives back to his old neighbourhood, watch the background of the wide shot as he is stopping the car. In the close-up that follows when Noodles gets out, two girls have appeared, hanging around a doorway, who were not to be seen the moment before.
Continuity mistake: When Noodles is raping Roberta in the car, her socks are pale brown-grey, then camera angle changes, and they are black, and then they are grey-brown again.
Revealing mistake: When a man is shot in the head, the bullet hits his hat, and it's very obvious there's no real bullet wound, his hat just opens and reveals a red hat he's wearing.
Factual error: Noodles visits the mausoleum containing the caskets of his friends who were killed in 1933. He finds a key hanging on the wall from a plaque that says Noodles built it in 1967. Earlier, he tells Fat Moe he had not been in town for 35 years, since 1933, so the action was taking place in 1968. The key is to a locker at a bus terminal. Inside the locker is a suitcase full of money, stacks of twenties. The bills have the signature of Secretary of the Treasury William Blumenthal, but he was appointed by President Carter in 1977.
Factual error: The Kate Smith recording of God Bless America was made in 1938. It is playing in the background during the opening scene but the opening scene takes place in 1933: 5 years before the song was recorded.
Factual error: Directors extended cut. Train leaving New York with Deborah for Hollywood you see the sign "voie 13." French for platform 13. The scene was shot at Gare du Nord, Paris, France. (02:55:23)
Character mistake: When on the phone to the police officer Sgt Halloran, noodles calls him Aiello. Danny Aiello is the real name of the actor.
Suggested correction: In the scene you're referring to, the person Noodles calls, and the character Danny Aiello plays, was the police chief, not Sgt Halloran. In the film, Danny Aiello is credited as Police Chief Aiello. Also, his wife (played by Karen Shallo) is credited as Mrs. Aiello.