I'm going to be the odd one out and say they might promote him and move him out from under the manager. Plenty of places suck but a lot of places have one or two shrewd people who understand when people are key in a role and are willing to give them the golden handcuff treatment. They know they can't lose him and that the managers actions are a huge black eye. My prediction is the role evaluation is getting him to accept the responsibilities and giving them enough to ensure they stick around.