I don't see how cheating on your wife represents a fireable offense or especially "cause" that will void a contract. Hell, do you have any idea what percentage of these coaches have their little trysts? Not to mention top administrators, board of trustee types. I mean, if they all got fired for that. A lot of powerful and successful men tend to do that. It has to do with ego and well they have the opportunities. Maybe it was something worse than simple adultry.
People cheat on their spouse all the time. I agree, if you fire everyone who did it, a lot of people would be unemployed.