Factual error: In the parade scene with Joey Zasa, they are having a raffle where they can win a Cadillac Eldorado. On the car a sign reads "Win THIS 1979 CADILLAC Diesel." The mistake: This a not a 1979 Cadillac Eldorado, it's a 1980 Cadillac Eldorado. The difference is the grill and a light under the headlights. The grill for the 1979 model has 14 spaces between the vertical metal beams, the 1980 model has 18 spaces between the vertical metal beams. Also the 1980 model has orange lights under the headlights, 1979 model has no such colour. Even though these two models are almost identical, there is a small difference in appearance. (01:17:55)
Factual error: When Keinszig (Swiss banker) gets killed, they knock over a pile of money including US dollars. They show US $100 bills with one problem - Ulysses S. Grant is on them. Benjamin Franklin should appear on the $100 bill. Grant is on the $50 bill. (02:28:45)
Factual error: The opening scene shows the 1979 NYC skyline with the World Financial Center (now known as Brookfield Place) visible, which wasn't built at that time.
Answer: It shows you how greedy they are even as they've made it to the zenith of their criminal careers. That's why you see Michael pass it on disgustedly and stare blankly into the ether. Michael's goal was never to be the boss or capo di tutti capi, he only did it to protect his father and then his family, his main goal. And at that moment he realises he's never getting out. He's a business man in a world of criminals (which he is himself).