First, yes there have been births to under age girls at YFZ. Remember the indictment of Dr. Barlowe - there's three, right there. One estimate was that 30 of the women had had children at 17 or younger.
Second, Feynman had problems with the source of attractions of gravity and singularities, I believe. Also, I mentioned those pages of errata and revisions of the "definitive" Lectures. Hawkings mentions one or two less than accurate positions of Mr. X, here http://plus.maths.org/issue18/features/hawking/index.html#
Yes the infamous Mr. X : ) Well it so happens that Feynman may get the last laugh. Hawkings and the rest of the bunch didn't predict that the Universe would or even could be expanding at an accelerating rate. Feynmans equations allow for that : )
Hawkings and the rest are now floundering looking to dark matter and energy to pull their bu*ts out of the fire : ) This game isn't over yet.