As is often the case, the point has floated past you.
The porn matter is a by-the-by. If he wants to watch on his own computer and in his own time, that's his business.
It is the context of the event(s) and the lack of integrity inherent in his behavior and the attempts to both dodge consequences and maintain employment in a situation where integrity is not just a like-to-have, it is imperative.
If he can't monitor his own, he has no right to sit in judgement on others.