My observation is that Buffon has gone over the edge with Juve. He's gone from screaming into his own net over boneheaded defensive mistakes to the sort of exasperated, "WTF can I do?" complacency that is taking form in things like the howler against Gatusso plus post-match laughter. The guy is losing it, mentally, and is out of the competitive zone of his we've come to know and love over the years.
