From what i know, the Pro's have amazing access to just about anything. Think about all the connections they have and people they have met over the years. I mean i've personally met hundreds of people who use gear and were very open about how to get it. Had no problem sharing their source.
This circle of people is smaller than you think at a higher level.
I know for a fact that an UGL up near Fort Worth was selling AAS to several Pro's 10 years ago. A good friend of mine knew the source personally and i actually met him and saw his "lab". It was a very legit setup and his gear was not cheap.
The high level guys who get busted almost always have UGL gear.
I do believe they would prefer HG gear, but that shit is expensive and very few BBer's have that kind of money. Just the cost of GH is insane, unless you get the generic Chinese stuff.
With all the money Jay's had over the years, i wouldn't be surprised if he was using legit HG gear, but there is no way to know. Only Jay knows.