Why is this odd?

If he started two years later and there was not a trace of the Prize work at the company, that would be an indicator that the competition was not important. If he started and could still see knock-on effects from the competition, that's an indicator that it was important.

Plus, he didn't just start at Netflix. He "took over the small team that was working and maintaining the rating prediction algorithm that included the first year Progress Prize solution."

Yeah, that sounds like he has some authority on the matter.