From what I can tell after reading the first page of that thread, there is no meaningful evidence either way.
It is circumstantially possible that he might have taken them. But he said he didn't and his physique seems achievable without them.
So all a juror would have to work with is the character issue. Either they want to believe he was natural or they want to believe anyone with a legendary physique had to be juiced.
While I admit to being one of the former, there is plenty of room for reasonable doubt... and an accused is innocent until proven guilty.