I think he went to Black Hat because unlike Defcon, Black Hat is run by a large multinational media company with a PR department trained and motivated to secure keynote speakers who will attract the most press attention to the conference.
What is astonishing by that? They can easily be splicing fiber cables taking a copy of most Internet traffic and recording either the actual call or just the from/to/length info and his answer is totally correct. It is actually a really terrible question.
