Do all authors climb every route they describe in their books? How could his route description get someone hurt, exactly?
If the book says "Walk off cliff," are you going to do it? Rather, the book says, "Follow obvious notch/ledge/tree," and we're all left going, "Huh?" The book helps out, but it's up to you (a little personal responsibility lesson here) to make your own decisions regarding your safety.
Granted, if the book says 50m rappel and it's 60m, there's good reason to complain. Which is why I want to here exactly how Nelson's description, "...could get someone hurt."