I thought I had given consideration. I do not regard "I don't know" as giving up. Giving up would be not finding the answer eventually. I certainly don't find myself "under" some other person if they know the answer to a particular technical question.

As for interviewing a luminary of open source what would be the difference? I imagine they (much like everyone else) don't know lots of things and are probably comfortable saying so. Their answers to how they would go about finding an answer would probably be wonderful.