not testing for it doesn't make it less illegal
that's like speeding on the highway, and saying because you didn't get caught, you didn't speed... Would that mean cheating on your wife isn't cheating unless you got caught?
besides, MLB not testing for it doesn't make it less illegal... it was illegal for him to buy it, and it was illegal for him to use it... Buying drugs... from illegal drug sources... nothing wrong there!
and he still says he didn't do it... if there was nothing wrong with what he did, he'd own up to it... he's covering it up.... innocent people don't often cover this kind of thing up!