I was just looking for the link:

http://lesswrong.com/lw/1f4/less_wrong_qa_with_eliezer_yudkowsky_ask_your/197s

"As far as I'm concerned, these are eminent scientists from outside the field that I work in, and I have no evidence that they did anything more than snap judgment of my own subject material. It's not that I have specific reason to distrust these people - the main name I recognize is Horvitz and a fine name it is. But the prior probabilities are not good here."