Explanatory material in the handbook is not official NFPA interpretations it is simply opinion of whoever authored it. Mike Holt's books, videos, live presentations are no different, any explanations he makes is his ideas/opinions and not any kind of official NFPA interpretation either. People that present such kinds of information often have a fair amount of credibility to back them up may even be able to quote CMP comments, reports, etc. to help back up some of what they say, still are not official representation of NFPA though.