I never claimed it was.
He was busted for a non-enhancing amount of a performance enhancing drug. That is a known fact.
He had a story that it was all someone else's fault and that he was entirely ignorant of it. This was accepted by the authorities, but I'm under no obligation to accept it. For all we factually know, he had a performance enhancing amount of the same drug in his system, and thought his body would have cleared it before the test, but still had a trace amount in his system, which came to light.
To my understanding, a 2 year ban is automatic for anyone found with any quantity of a banned substance (enhancing or otherwise).
Tennis authorities bent over backwards to avoid busting the arse of their #1 player and biggest draw.
I've no problem with him as a player (though I prefer watching Alcatraz, in the same way I preferred watching Federer over Nadal or Djokovic). But IMO he's a drugs cheat - whether wittingly or not. He had a banned substance in his system, and a story that made it all so done else's fault.