Perhaps you are referring to Lee's Tao of JKD?

Excellent book and one that every martial artist should read and have in their library (and it isn't that expensive really)

Lee's views on traditional martial arts are controversial but I do believe that anyone who has studied martial arts seriously can appreciate the philosophical tone of this book (if in fact this is the one you are referring to)

I think that your issue is this ...too many of us get too into dictated technique and form as well as tradition to appreciate Lee's theories.

I love "google fu" but I haven't found the book either. It was what latinorockiee sent me in a message. 

Bruce Lee never wrote a Principles of Jeet Kune Do, so I'm not sure what it is you're reading.  There's a Tao of Jeet Kune Do, which is nowhere near 437 pages.  There's a Bruce Lee Library compendium series, but none of them are named Principles either.  Maybe you're finding mistakes because you're reading a book that's not really by Bruce Lee?

Having said that, get comfortable with criticizing your idols.  Bruce Lee was a tremendously gifted natural athlete who trained like a maniac.  His natural athleticism, good looks, and ability to self promote took him very far in life.  He was a notable philosopher in a field (martial arts) in which there are too many people who regurgitate the "philosophy" of their teachers without understanding.  But he was certainly not the "best martial artist", however you want to define a term that nebulous.  He was a known plagarist, and it's probable that he lied as part of his self promotion.

The faster you learn to question your idols, your teachers, your styles, and even your styles' founders (and I don't mean questioning just to be a jerk, I mean questioning for understanding, and criticism only when warranted), the faster you'll approach an understanding of martial arts that comes from your own development instead of one that's handed down to you prepackaged.