I commend you for having a forgiving spirit for a family member. Note, family member.
I fail to see how the analogy fits when we're talking about a business situation versus a family situation.
My view on Petrino has changed over the years. It was his time at Arkansas that sealed the deal with me. It was not the point he had an affair. (though that does weigh heavily.) My issue with Petrino and his time at Arkansas was the financial liability he put the school through. They, UArk, were a hair away from a lawsuit where dozens of applicants could have, and in my opinion should have, brought a suit against the school when he hired Dorrell instead of more qualified applicants.
The way Petrino has left jobs demonstrates what I can only term as a devious type of personality. When he had an affair that spoke to his moral character. When he put the University of Arkansas in a position where they could have faced numerous lawsuits? That speaks to his total disregard for the well being of others.
Let's assume you're a business owner and you're interviewing for an open position in your company. You find out, through the vetting process, that one of your prospects has basically willfully ignored his former company's policy, hired a mistress which goes against employment regulations, paid off said mistress, and lied to his former boss...are you suggesting you're going to just forgive, forget, and move forward?
(As to his affair, I've grown to learn if a man, or woman, does step out on their spouse they are just as likely to steal, lie, cheat, you name it. The affair itself would have been enough for me to fire him. However, in today's age, I realize my moral compass points differently than a lot.)