For some reason while watching Ocean's Thirteen the one thing that jumped out at me was the repeated reference to shaking of Frank Sinatra's hand. This occurs earlier in the movie during a flashback with both Willy and Reuben shaking Sinatra's hand.
It also occurs near the end of the movie, when Daniel Ocean states to Willy Bank "You shook Sinatra's hand - you should know better."
What did Ocean mean by this?