Don't know him. But,
There was nothing intrinsically unsafe in his decision to allow the passenger on the flight deck.
There isn't anything intrinsically unsafe about letting me onto the flight deck, I've been there many times pre-9/11.
There isn't anything intrinsically unsafe about letting a pilot airside with a Thermos flask full of tea.
But the rules -- daft as I think they are -- say it can't happen.
He was on a final warning and breached one of those rules.
End of.