When Ann arrives at the restaurant and is standing at the bar, she is wearing black heels. Then, as she walks over to look at the paintings with Primo, she is wearing flat white shoes. When she later dances with Primo, she is wearing black heels again.
When Bob is talking to Secondo in the Cadillac, his lollipop is alternately in/out of his mouth between shots.
Secondo's arm when talking to Phyllis in the car.
Toward the end when Secando is walking back to the restaurant and the car sale drives away, the Grover's side tail light is out. It's supposedly a brand new Cadillac.
The pianist in Pascal's restaurant is playing an electronic keyboard, the likes of which would not be invented for another twenty years or more.
In the final scene of the "big night" dinner the wine bottles across the table and in the kitchen with Secondo all have the trademark pink DOCG label on the bottle stem. The DOCG pink label was released in Italy only in the 1990s; the movie is set in the 1950s.
When Pascal plays the piano at the end of the big night, his fingers don't correspond to the music that is heard.
In the fight on the beach there are shadows of crew on the two brothers for several seconds.