^^ Yes. I had an interesting exchange with Demile back in the late 90sk where I talked to him about whether BL had used 'fa-jing', or ground-path energy. Most Chinese martial systems use a version of this ground-path, found chiefly in Chen style Taiji. Anyway he claimed to never have heard of it. When I described it as a method of energy expression which uses the pelvic floor and tantien to issue power using the ground-path with very little rebound.
He said that his method of the 1 and 3" punch did not use that, and he did talk about the concept of Jack Dempsey's 'falling step' as being involved.
I found it very strange that in this era where nearly anyone interested in 'short power', would surely know about 'fa-jing' (or fa-jin) and the neijia arts that Demile had never even heard of it.
I do find him honest and forthright in his interviews and I have trained the inch-punch using his methods (his first book) and they do work.
He's not someone to give props lightly, I find him a bit of an egotist like Joe Lewis, so anything he say about Bruce Lee is going to be truthful, since he rarely compliments people.