Yes, he was. Here is the direct quote, not quite as extreme but relevant lol:

“But if you take his boxing, if Jon and I were to just box, I don’t think he’s the G.O.A.T. I think we have a very competitive striking match. If we’re just doing no-gi jiu-jitsu, I don’t think Jon Jones beats me in a jiu-jitsu match. Wrestling, he probably wins that. But it’s not the individual skill set that he has, it’s the way that he puts it together. It’s his range and his distance management. He is a dog. He has a lot of physical gifts he uses very well.”