Vito didn't ask Michael to kill Sol and Mac--he was too weak to even ask the nurse at the hospital for a bedpan. And, he was anguished and dismayed when he returned home from the hospital and Tom told him that Michael had killed Sol and Mac. Sonny and Tom didn't ask Michael to kill So and Mac--"Maybe we should leave Mike out of this"..."Madonn', the old man would have my head if I got you involved in this." Michael volunteered to kill them--he wanted to kill them.

The novel tells us there was a strong personal element for Michael. After Mac broke his jaw, and before he passed out, Michael "...wanted to hide the delicious icy chilliness that controlled his brain, the surge of wintry cold hatred that pervaded his body. He wanted to give no warning to anyone in this world as to how he felt at this moment." Later, in the restaurant with Sol and Mac, Michael, sensing that Sol is talking down to him, "...felt that strange delicious chill filling his body." And, he smiles at Mac before shooting him.