The short answer was that I've never read his stuff.
I read. A lot. But there is a huge amount of information out there. There are experts I haven't read. Many of them. People I've never studied with. Months ago, I did a post on possibly working up a course for extreme CQ gun, specifically deploying under attack... and a lot of people gave me leads on work already going on. That was a relief. The late Jim Cirrillo or Southnarc or Mercop are the people who have had to do it and someone in the middle of the problem will tend to understand it far better than someone who has only brushed at the edges.
The list is long, and I make it longer by reading sometimes skeptically. If an author intrigues me, I tend to dig into his bibliography, and sometimes an author's sources do not say what he claims. I like reading on the edge of the field. I know what it feels like to be in certain kinds of problems, have developed a comfort level. I actually learn less from people with similar experiences than I do from researchers or sometimes reporters. If you know human pack behavior, sometimes books about dogs or apes will give a new piece of the puzzle.
Anyway, Paul very graciously sent a copy of "Principles of Personal Defense." It was a short book, I read it while waiting for the coffee to brew. But it was concise, accurate and wonderful. The reading list grows.