Revealing mistake: In scene at the brothel, with the senator and the dead prostitute, the supposedly dead body is breathing in the last shot of her, just after Tom Hagen says "it'll be as if she never existed". (01:15:30)
Revealing mistake: In the opening scene you can see Paolo breathing, despite him being dead and all. [If you have trouble seeing it, watch the shadow on his back move up and down as he breathes.] (00:03:05)
Chosen answer: Vito was born December 7, 1891, so he was 9 when he moved (Godfather II states: "In 1901, the family of nine-year-old Vito Andolini is killed"). However, it was by the early 1930's that Vito had established his criminal organization as the Corleone crime family, with him at the head. He died in July of 1955, making him 63 when he died. In real life, Marlon Brando, who played Don Corleone, was 47 at the time of filming.
Bishop73