Doping

If he's not governed by anti-doping rules (sportives, surely) then what's the problem?

Also, could it not be in his system for medical reasons? Since he's not riding Le Tour, etc I doubt he'd be too familiar with WADA's list.

I used to give EPO regularly to patients in kidney failure (one of kidneys functions is to help with red cell production) to avoid blood transfusions (means more foreign antibodies in blood which could affect getting transplants later on).

EPO may also be used more liberally in America for things like anaemia (means they can charge more from health insurance for expensive EPO compared to cheap iron tablets which they'd use here).

Or...he could just be a cheating cunt.