Doping

But does he, really?

I'm sure his spirometry results will be part of his defence submission, the people who have to judge him will know whether he has asthma or not

Which is presumably where the asthma diagnosis came from?

It's more likely that the asthma diagnosis came from either his own GP or from a previous team doctor, since he claims to have a history of asthma which I assume predates joining OGE.