Why? What is he going to say...He sucks?
No kidding. Truth is that coaches aren't as partial about rivalries as the fans are. You also see coaches of rival teams friends with each other.
Being a head coach in the state for several years, I'm sure Mac saw him play before and even tried to make a recruiting pitch. As a coach, you look at players for their talent and personality, and not which team's uniform they have on.
I think coach would lose a lot of credibility in the state if he threw Iowa High School kids under the bus in interviews....