He mentions at 14:00 the "Dark Brown" experience, where he went to Brown University to make the HyperText system. He says "he had to work under a torrent of insults from someone who he thought was his friend and HyperText got dumbed down."

Though he doesn't mention who the "friend" was, is it the much-beloved (by Brown CS dept) Andy van Dam (who is credited as the co-designer of HES)?

https://en.wikipedia.org/wiki/Andries_van_Dam