I see no problem with what he did. Allowing her to continue to spread lies about what was happening behind his back, when he had hard evidence to support his claims about her would have allowed her to move on to the next sucker on her list. He suffered being a fool so the next old millionaire has a chance of avoiding her machinations. Exposing her to their peer group, especially those she was most likely telling an alternative story (lies) to, seems perfectly fine to me.
Shoot, dude even had pictures to seal the deal. So he did not just come with accusations, he came there with a briefcase of irrefutable evidence. So let them both suffer for their collective overweening egos. His being she wanted him for anything other than his money. Hers being that she was so smart that he would never catch her infidelity or she had so much influence over him that he would never publicly expose her if he did catch her. Either way, both allowed their egos to lead them down this path.
Shoot, dude even had pictures to seal the deal. So he did not just come with accusations, he came there with a briefcase of irrefutable evidence. So let them both suffer for their collective overweening egos. His being she wanted him for anything other than his money. Hers being that she was so smart that he would never catch her infidelity or she had so much influence over him that he would never publicly expose her if he did catch her. Either way, both allowed their egos to lead them down this path.