Neri's only real - yet questionable error in any of the 3 movie's is when he tells Vince to whack Zasa. He gave the order directly without the okay from Mike. I think, even though he did so, he felt he was doing so for the best of the family and for Mike to whom he was so loyal. Also, I feel Mike only displayed his disapproval for the order being given because of Neri's reputation and following of orders in the past. Again, showing Neri's position in the organization.