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.
Once Upon a Time in America (1984)
1 revealing mistake - chronological order
Directed by: Sergio Leone
Starring: Robert De Niro, James Woods, Danny Aiello, Joe Pesci, Burt Young, Treat Williams, Elizabeth McGovern
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.
Police Chief Aiello: I'm the chief of police, not the chief of the people.
More questions & answers from Once Upon a Time in America
Answer: You have a censored version. The American R1 version has no such censoring.