Its sounds like this was a longer term type thing. Not a one-time oopsy. It would not surprise me if they both had feelings for each other and this was more than just sex.
I will say that I agree she was an adult and this sounds consensual, so she doesn't get a full pass. But, he is much worse here. Setting aside his marriage, kids, and alleged faith, he is much older, her boss, wealthy, powerful. There was a power imbalance here. He wasn't fired because he cheated on his wife. That is what he did morally wrong here. He was fired because he slept with an employee, which exposes him and Michigan to tremendous exposure as it can be a form of sexual harassment depending on the circumstances. She likely will not be fired, and if anything, she probably will sue the school and get a quite, six-figure check. That's how this shit usually goes down.