Not at all. He tested positive after rehabbing his broken leg. That's likely the reason he recovered ahead of schedule. People act like Silva came into the ring with a chiseled physique. He had the flabbiest midsection of his whole career in the last fight. He has never had the build of a juicer.
I guess you took the BS hook line and sinker. Several banned substances were found in his system...including a weight cutting steroid...He switched his excuse from "I never did it" to the built in excuse "I needed it to heal my leg"...although the healing properties of the steroids he tested positive for are highly questionable considering there are far more effective remedies out there like HGH. I understand that this was the first time he was ever tested inside of his camp for a fight. Using steroids is not necessarily going to make someone look like a bodybuilder, especially with Silva's genetics. He looked exactly the same as he has always looked throughout his career, which doesn't bode well for the excuse that "he only juiced for this fight".
It is implausible that this was a one off. What did Silva see in a smaller, over the hill, inferior striker, who was tailor made, that made him feel the need to use PEDS? It's more likely he's been juicing since prior to the Diaz fight.
Pending his result against Connor Mcgregor, I would rank Featherweight champ Jose Aldo ahead of Silva too.
Silva also had several embarrassing losses early and mid way through his career. His loses to Weidman had nothing to do with age. Silva was still in his prime. Even in this last fight with Diaz his reflexes and speed were just as good as ever. Weidman is just a great fighter,quite possibly the best Silva has ever fought in his career, and it also was the worst possible style match up for him. I actually picked Weidman to knock him out before their first fight and I believe he would have beaten any version of Silva.
His opponents were likely juicing as well, but since that fact about them will probably never be revealed, yes his legacy will take a hit.