As I said, poor understanding of statistics has been a beneficial trait in many areas of research for decades now. Universities and labs are rewarded with funding because they are able to (honestly, but incorrectly) pump out more "results" than if the researchers were properly trained.
So the issue goes well beyond the problems "not being called out". The problems are institutionalized. Editors and reviewers will try to force you to commit the errors in order to publish (and hence have a career). That is what they have been trained to consider science.
Could easily have been a handy reference text for lending or showing to erring students/faculty.
Assuming the book is for his own learning, as opposed just curiosity or for students etc, there is still nothing wrong with learning from book. Assuming he really dont know the statistics.
And it definitely beats up people who don't know either, but prefer to stay ignorant just so they don't look like someone who reads beginners book.
This is definitely true. I once saw a book with a title similar to "Statistics for Dummies" in a professors office. He had plenty of access to staticians at the university too. Unfortunately if a given field involves many people with ignorance of statistics, these problems may not be called out during the peer review process.