I know that. Freeman Dyson was his friend. The author of this article was not his friend, so it would be cool to use "Johnny" in a quote. Using it in every reference is weird, false familiarity, kind of disrespectful.
How do you feel about calling William Jefferson Clinton "Bill Clinton"?
That is, was "Johnny" something his friends called him, or what he called himself in general when introducing himself to people? I'm getting the impression it was more the latter.
