Too "deadly" for MMA?

I've previously mentioned that I once interviewed a "reality based self defence expert" on my radio show. The subject came around to fighting in the ring/cage and he opined that he didn't spar because his techniques were "too deadly". Then he added that if he ever got into the ring/cage he didn't know what would happen. "I'd most probably kill someone," he said. I had to hand it to my other guest, Sifu Vincent (a man who has considerable ring experience). He was so diplomatic and self-effacing in the way that he dealt with this (absurd) statement. (I remember he said something like: "Really? Oh my! You see, unlike yourself, I really don't know how I would fare in a real confrontation!") Of course, the RBSD "expert" was full of it. Sparring isn't fighting, that's clearly true . But if you never spar (at least in some fashion), you never get past the starting block in terms of judging what you...