Except that's a strawman argument. He said there's no data set specifically in the Olympics to prove that, which would make sense seeing how few people actually end up with the genetics and opportunities in life to end up there, and how many fewer of those would actually end up being transexual.

There are, on the other hand, mountains of evidence (which do not have to come specifically from the Olympics) to support that testosterone gives quite an advantage to doing pretty much anything physical, especially strength related. This is also why anabolic steroids (which raise testosterone) are banned in pretty much all major sporting events. It's not saying testosterone is such a HUGE advantage that the average joe could just head to the Olympics and start medaling women's events, but it is enough of an advantage to make someone who would otherwise be average at best into a top competitor.