Do you know how many different ways there are of being tested positive? After his swearing he never purposely took steroids at the hearings, there is no one stupid enough to risk getting caught by taking them.
I think he didn't take steroids, at least not knowingly, and with all the things sold over the counter that contain a banned substance, I doubt very much he's guilty of anything except not being cautious enough when taking over the counter medications or food supplements.
I think he's innocent... I also think he's being the good sportsman he is by taking this the way he is.