Regarding the complex phone arrangement: There's an effect, the name escapes me, that adding security can make threats less frequent but more dangerous. Sounds like he was more complacent because he had trust in his phone system.

And I agree about author - if he had said that he violated an easy rule and owned that I would take his credentials more seriously. Everyone makes mistakes, but he didn't list this simple, well-known rule as a way of preventing this.