I agree with all your points. When I said treat this in a "responsible disclosure" method, I did really mean a grace period, for the authors sake[0]. Clearly the reasoning is not the same as a security issue, as you pointed out. I was trying to be a bit clever. My mistake.
That all said, I still think we can treat each other better. Honest question: was it necessary to destroy it in such detail? Was it necessary for the effort of attack on the "crypto box" front? It seemed personal.
[0] Contacting the author first doesn't necessarily preclude timely notice "this book is flawed" out to readers.