When people say hes squeaky clean, it's because for the last 19 years, in the media, he has been. Hes the poster child for gracious winning and losing. So while we can't (except those actually involved) speak to things in his private life, all we have to go on is what we see.
Bill Cosby and OJ Simpson also seemed like great guys and now we know different. But what I wonder is has Peyton been involved in anything bad since this supposed incident? If not, lets not cast aside all the good hes done since. OJ and Cosby were well beyond college when they did bad things. Does the same go for Peyton?