https://www.thoroughbreddailynews.com/ny-horses-from-federally-indicted-trainers-were-positive-for-clenbuterol-at-77/

From what I've read so far, I'm inclined to believe that the success of Jason Servis (not necessarily Navarro) was more likely due to his use of corticosteroids than SGF-1000. I also think Servis and Navarro were not alone in abusing this class of drugs. Mark Casse complained about this with respect to clenbuterol earlier this year:

https://www.thoroughbreddailynews.com/op-ed-clenbuterol-it-has-to-be-stopped-and-now/

I also note that Gamine's positive in the Oaks was for a corticosteroid. Baffert did not deny that it was administered, only that it was administered within 14 days before the Oaks.