On a related note, even though the majority of GF II is devoted to showing how ruthless and calculating Michael had become since his college boy days of Godfather I, don't you think his allowing Pentangelli the opportunity to attone for his betrayal on his own terms shows that he still had some compassion left inside him. Tessio had an even deeper history with the Corleone Family than Pentangelli had, and Michael had no problem ordering his violent death. While it is true that Michael never really had any "business" relationship with Tessio like he would have had with Pentangelli, I still think he would have given Tessio the chance to attone for his disloyalty out of respect for his father. In a sense, by showing this "softer" side of Michael(if you can call ordering someone to kill themselves soft ) makes it seem at least plausible that his character could have undergone the transformation it did from the absolute killer of Part II to the old man who just wanted out in Part III. He was still cold-blooded, but at least the seed of the Part III penance he seeks was planted at the end of Part II.