... the author wrote a book on the topic, and teaches a fairly famous course on it. I'd hope you'd give those credentials at least as much weight as some HN self-proclaimed expert.
Context: You disparage someone as simply touting their personal anecdote, and ask if anyone around here is a "real" expert.
If someone had replied "why yes, actually I just wrote a book on the topic, and I teach a huge course on it," would you have accepted that person as being "versed" in the topic?
Can we at least agree that the author is actually more qualified than you seem to give credit for in your original post?