"I disagree that we should absolve him of all wrong doings"
I did not. If there was more to it, leaked confidentials, blackmailed deals etc. then yes, he will be responsible. There is an investigation. But what is known, so far he "just" cheated on his wife. And this is what they have to deal with.
Whether it happened or not I don't think is relevant, the lack of judgment in opening himself to blackmail, etc., was a lapse in judgment that at least IMHO disqualifies him from leading one of the most valuable and strategically important companies on the planet.
For what it's worth, I believe the military would agree, that would lead to a pretty quick loss of security clearances.
The dude isn't running a McDonalds franchise, after all. Everyone is saying he "took responsibility". No, he admitted it after it was already public (which is no great act of courage), now the board needs to actually make him accountable. And unemployed.