Former UFC referee John McCarthy believes that Jon Jones did not knowingly take steroids and that the former UFC champion is a victim of tainted supplements.

During an appearance on the MMA Junkie Radio, the veteran opened up about the topic and added that unregulated supplements could be what worked against Jones.
“When you’re an athlete making the amount of money that Jon is making, you can’t go to the AM-PM and buy something that’s in pill form and put that in your mouth without going, ‘What the (expletive) are you doing?’ C’mon, dude. You are a frickin’ Ferrari. You can’t do those things. You have got to be smart. And I just don’t see the letting him off with, ‘Oh, it was just a mistake,’ because he’s had that mistake before.” He said.
The Rocky Past
Interestingly, McCarthy and Jones did not have one of the best working relationships. Back at UFC 200, where Jones was supposed to fight Daniel Cormier for the UFC Lightheavyweight championship, Jones had tried to remove McCarthy as referee. Jones claimed that he did not agree with the ‘energy’ of McCarthy and asked UFC not to let McCarthy referee the title fight.
Despite this, McCarthy said that he loves Jones and added that Jones is one of the best MMA fighters out there.
“I love Jon Jones. I say he’s the greatest MMA fighter I’ve ever seen. But this is where the problem comes forward. I don’t personally believe Jon took some type of steroid before fighting Daniel Cormier. … But Jon is personally responsible as a professional athlete under contract with the UFC … with everything he puts in his body. And I believe that Jon is taking – or allowing things that are not known or not tested – and because some other trace element is in there that makes you pop, you’re responsible for it,” McCarthy added.
Jones is currently in a bad situation after his fighting license was revoked by the California Athletic Commission after he failed a doping test related to his UFC 214 fight against Daniel Cormier. He cannot apply for a new license in the state until his case with the USADA is solved.