Nice stats DR! Thanks for supporting the fact that you can get a nice cycling performance on a vegan diet, against popular (and ignorant) belief.
There isn't any data (that I know of) that supports the idea that one can have an above average (better) racing performance whilst being a vegan. However, there isn't any data that tells the opposite. It all depends on how your body reacts. Some react better to a carnivorous diet, others don't.
If you are a vegan for athletic reasons (not because of ideals and ethics related to animal eating, etc.) then I agree that there is no point in arguing.
For athletes that base their diets purely on professional reasons, it is a matter of finding the one that suits you and your body better. If one concludes that he achieves better results on a meat based diet, he should go for it.
There are lots of successful vegetarian/vegan athletes (Carl Lewis, Robert Parish..), including endurance ones like Dave Scott (the guy that held the record for most Iron Man wins, matched only 8 years later) and many others I can't recall at the moment.