My personal impression is that John Carmack has the ability to organize concepts in a way that few people can. So even if he's pretty clueless about the topic now, I would expect him to reduce some maths papers to their essence in a way that nobody else did.

I mean also for Oculus, reprojection in a pixel shader seems like an obvious and easy solution in hindsight. But nobody had tried that before he did. Plenty of people (myself included) knew the math. But we all missed its application to the issue at hand.