The WM who work on base under a different command received Non-Judicial Punishment and was reduced to the Pvt and I believe forfeited some base pay.
As Joe Marine 76 pointed out about an adultery case he handled, it can be handled entirely as a non-judicial punishment. That means it could be as little as a reprimand, a letter, or a loss of pay.
I believe Gen George Casey would have been Petraeus' military superior at the time, but I don't remember exactly. If so, then I'm convinced Casey would have simply recommended over coffee or beer to Gen Petraeus that he quietly retire.
My point about penetration was with regard to the law in general, civil and UCMJ.
I just heard on Fox that the affair took place after he assumed D/CIA. The affair evidently DID NOT take place during the time he was the Commander in Afghanistan or while the bio was being researched and written.
Therefore, Petraeus was NOT subject to UCMJ while the alleged adultery took place.
I think we can all agree on that.