I'm with Scalish, if Leonardo was in the game 100% he would have been clipped with his brother and Grandfather because he would have been a threat with the Rizzuto name. He was left alone I think because he didn't have a hand in LCN in Montreal. Yes he might have been behind some dirty deals with his father but that doesn't mean he is LCN through and through.

Now Nicolo and Nick Jr. WERE in the game and it cost them their lives. Why clip them but not Leonardo if he was considered a powerful figure? I see no reason to think he is a major player and don't see how Montreal would all of a sudden listen to a lawyer even if his name is Rizzuto.