I've read a lot of Keith's writings. In the late sixties and way on into the seventies, Sixguns was my handgun Bible. I read it over and over and over. I even took the book on trips with me, and annotated my copy of it with my own thoughts and data. The majority of my handloads were based on Keith data. He was something of a hero to me when I was a younger man, the man who had all the answers to my sixgun questions.
That said, just because you're a famous gun writer, guru, sportsman, whatever doesn't put you above the law. In retrospect (and this eagle incident, if true, is a good example), Keith now seems something of a showoff to me and more than a little egotistical. He would not be a role model for me today as he was over forty years ago. He would no longer be one of the Gods of Guns for me.
While it may be true that eagles eat lambs, fawns, etc., that's part of the natural order of things. Keith inserted himself into that natural order, killed an eagle just because he didn't "like" it or the law that was enacted to protect it, and had no plans to eat it. Even animals don't kill for "sport".