I saw Sunstein lose it at CLS.  He gave a lecture supporting Catherine McKinnon's anti-pornography ordinance.  Sunstein argued that pornography was low value speech -- being just a "masturbatory aide" -- and thus could constitutionally be subject to banning.  After the lecture (held in the fifth floor handle of the "toaster,"  professor Andrzej Rapaczynski made the point that many works considered pornographic -- like those by the Marquis de Sade -- were also very political and therefore "high value" speech.  In response, Sunstein lost it, and started yelling at Rapaczynski accusing him of just wanting to be able to look at dirty pictures.

This was on the heels of a then very recent, very popular visiting professorship at Columbia, in which we who took Sunstein's Administrative Law class idolized him.  He taught Ad Law like what it is -- high octane constitutional law.

The point is simply that Sunstein in person can get overwrought and flaky when he's been working too hard and hasn't been getting enough sleep.  He does have feet of clay.