Sorry, your Amazon link only directs me to the book title. My query produced 0 results. "No reference to 'something from nothing' in this book". The term "nothing" did not appear in the lecture as far as I could tell.
Even if you can boil the first something down to "an ordinary point of space and time", it would still be something, even if extremely discrete. What causes space or time to exist?
While I'm sure Hawking's view is a brilliant explanation for the formation of the universe, it still does not support the something from nothing position, in my opinion. Perhaps he holds your view (though I have yet to see it), but supporting it scientifically is something else altogether.
I did find this statement in his book: "Because energy cannot be created out of nothing, one of the partners in a particle/antiparticle pair will have positive energy, and the other partner negative energy."
Without redefining the universe as a big cumultive "nothing", or rethinking conservation, something from nothing does not work.
This is just a confusing way of trying to sneak the law of causality back onto the discussion. There is no scientific law of conservation of causality, just as there is no scientific law of the conservation of something-ness. there is nothing that can "not work", because there is not work to be done. "Causality" or "something-ness" is a human classification scheme, not a force of nature. As per your reference to Hawking--first there was nothing, then there was a particle and its anti-particle. Energy was conserved, which is a scientific law. Something-ness was not, because it ain't.
This is a prime example of using the fallacy of the excluded middle to make an argument.