I think you are right, but he could have got the address. Believe it or not people use gamertags on facebook accounts and all sorts. Would not be to hard to track an address I guess in this day and age with kids linking all sorts of sites together.
searching a gamer tag can often reveal facebook pages etc. email address linking to facebook and nobody checks their privacy settings etc.
I'm inclined to say the story is BS. Is the article in the OP a reputable website?
Although the pizza theory could be possible