How does he explain the spread of the newly mutated gene? Mostly these spread by diffusion; even considering air-travel. Are there travel patterns that go around Africa?
There was very little diffusion few thousand years ago, [his putative dating]. Indo-European counterclockwise swing did happen in that time frame, but did not impact on the East Asians, and surely did not impact on the population of the Americas. That's why I question his timing - from Occam's principle it would be so much simpler to date that mutation [or the whole cascade of them] to as yet undifferentiated out-of-Africa group [100-110 to ca.40 Kyrs before the present]. More, such time conveniently pre-dates the settlement of the Americas.