Obviously, I along with every sane person here is so sorry to hear about this.
The advice given to you so far has been spot on, and you handled it great. I can only add this with the hope that it can maybe keep you from worrying.
My experience with threats is the ones who make threats to you are not the ones you need to worry about. They generally never act on them. It's the ones who don't say a word who are the real whack jobs, but since they don't say a word we always are not aware of what is cooking inside them anyway.
Of course no one can ever guarantee anything, and it always pays to be smart like the previous posters say, but this sounds like the kind of guy who gets his from the threats, not from taking action.
So sleep peacefully and try not to worry. We'll never know why people do this but I'd bet everything I own that nothing at all will come of these threats.
That said, blacklist him as the mental anguish alone is bad enough for anyone to have to endure.
you handled a bad situation as well as one could.
-- Modified on 9/16/2013 4:44:29 PM
-- Modified on 9/16/2013 5:40:33 PM