I've watched that lecture a couple times and never even thought what he was doing was bad until you called him out for it. And even still, I think he handled it very well.

I've seen people ask questions to try to get recognition in groups, and when they don't get it, they childishly leave the meeting.

This was a moment where I gained a lot of respect for Dave McClure: https://youtu.be/25TxrhsXFvs?t=46m14s

I've had 4 different choir directors through my life. The best was a man in high school that would get angry, throw his baton down, and walk out (of band). Never saw him do that in choir but I heard about it. He demanded that we were focused. In the select choir, all members were required to perform solos. I wasn't ready for mine, but he still forced me to do it (he refused to continue class until I sang). He was, beyond comparison, a better director than the others and the choir showed it.

Going back to Paul Graham, even if he didn't handle that as well as you think he should have, his overall personality certainly makes up for it. Anyway, it's good to see that he'll be honest and you can trust him to do that.