You're right, I misremembered how Master was trained because they already had developed Zero by then. I still don't think there's any reason to believe Zero would do worse against humans than the Lee version. Zero was much stronger than Master, which was initially trained on human games. If the consequent self-play learning caused any non-transitive relation to humans, it sure wasn't evident when Master played against humans. So why would it show up in the learning of Zero given how much stronger it is than Master. You would have a better case if there was a reason to believe humans played anywhere near optimally.