I knew Professor McCarthy at SAIL back in the day when the Colossal Cave Adventure was making the rounds in the mid-70's. Besides the technical acuity you would expect from the Director, he was genuinely interested and looking for fresh insights in students' first encounter with a less-constrained text puzzle.
Noticed him in the audience a couple of times around 2006 at AI talks. He was really skeptical of the idea of the singularity or self-improving AGI and at the smaller talk he asked really tough questions of the speaker (Eliezer Yudkowsky). I was a community college student at the time and remember wondering how cool it would be to go to a school where one could have someone like that as a professor!