I am guessing he was referring to the GNU OS, hurd. In retrospect this is quite funny considering hurd has yet to see a (production) release to this day. http://www.gnu.org/software/hurd/hurd.html
Well, he was probably referring to the Hurd, a kernel which was/is supposed to be the official kernel for GNU (not GNU OS btw). As Linux came with a GNU userland from the start and the discussion is specifically about the kernel it's hard to imagine he meant something else.