Libby Judge Insults Amicus Law Professors?

From the AP report:

A federal judge said Thursday he will not delay a 2 1/2-year prison sentence for I. Lewis "Scooter" Libby in the CIA leak case, a ruling that could send the former White House aide to prison within weeks....

[U.S. District Judge Reggie B. Walton] never appeared to waver from his opinion that a delay was unwarranted. After 12 prominent law professors filed documents supporting Libby's request, the judge waved it off as "not something I would expect from a first-year in law school."

Maybe I'm missing the context, but this seems rather intemperate. I've read the motion, which is signed by leading constitutional law professors (Vikram Amar and our own Randy Barnett), leading criminal law commentator Alan Dershowitz, and Robert Bork, and which is signed as amici by the same people plus several other well-respected scholars. It's well-reasoned and extremely competent; I'm not sure I'd agree with it, but it makes a thoughtful and plausible case for its position. There seems to me no cause at all for the judge to react this way.

Thanks to Bill Patry for the pointer to the AP story.