Given the lengthy setup throughout BG that Rudolph was reckless, stupid, cowardly and had bad trigger discipline, I think that we shouldn't look further than this. Bradley remarked on it several times. Bradley also stepped to the side of the door at the childcare place -- because he was scarred that Rudolph would shoot him through the door.
This has been the description of Rudolph all through the series.
What I think is that Michael didn't attack Harry.
No, but Douglas hadn't murdered Michael's little girl in front of his eyes either. And lets be clear, it wasn't easy for Harry to get through to Michael.
The Warrior
Again the bat swept down, and Douglas fell senseless to the sand. Michael stood over the man for a moment, his entire body shaking, the bat still upraised. "Michael," I said quietly. "He hurt my little girl, Harry." He said with barely repressed rage."He isn't going to hurt her now," I said. "He hurt my little girl." "Michael," I said, gently, "you can't. If this is how it has to be, I'll do it. But you can't man."
So as I said, imagine if Michael's little girl had been murdered before his eyes and if he was also on the edge of exhaustion from battle.. Do you think Michael wouldn't have tried to go through Harry to get to Douglas? Also notice that Harry didn't want this good man, his friend, to become a monster, he offered to take his place.
When it was over, Michael's reaction and Harry's reaction is much the same to what they almost did.
Again, The Warrior
'Easy,easy," I told him. "We're done here. We're done." He stared for another long, silent moment. He lowered the bat, very slowly, and bowed his head. He stood there for a minute, his chest heaving, and dropped the bat. He settled down onto the sand with a wince. I got up and collected Fidelacchius, returning it to it's sheath. "Thank you," Michael said quietly. He offered me Amoracchious'shilt.
Harry did hurt his friends who were trying to stop him, so his shame was greater. However like Michael he thanked both Sanya and Butters for stopping him.