another reason is tho that a bodybuilder really can't be in denial. Could you imagaine Coleman looking someone in the face and saying he's never taken a steroid? i'd laugh at him (not out loud becasue he would end me, but in my head i'd be laughing)
Almost all pro's deny usage. Who can blame them, would you tell so one that you have probably never seen before that you take an illegal substance. That wouldn't be very smart.