I'd like to read the book, even though I'm not a fireman. Jim Mann is right; you can't write UFO's off as crackpot or fringe when official organizations like fire brigades are taking it seriously. The statement at the end sounds like a "fallback" to me. The brief reading given shows that it is the actual threat that the book deals with, not just the perceived one, otherwise it would just contain tips on how to drive a fire engine past over-zealous skywatchers etc.
(BTW: Sorry there's been no new material on HPANWO for a few days. I've been shivering in my sickbed. I'm a bit better now. I've got plenty more posts lined up!)