Depends how he loses (assuming he does), and what the fight was like. But most of the time at this level the loser is either gracious or kind of shrugs it off (if its a points loss they nearly always say, "I think I won the fight"). With Hopkins it's always unpredictable. The weigh-in, the fight, the post-fight. You just have to wait and see.
I seem to recall him complaining about the Taylor fights as well even though he did nowhere near enough to win.