Sometimes in the Midlands (and elsewhere, of course), people use the phrase 'has died' to mean that there is no longer any contact with them, perhaps as a result of a family conflict. I'm not surprised that you can't find any closure with such a gruff reply...If you are too shocked to bring yourself to call back his dad, maybe you could ask someone else (maybe of a different gender) to call him, and if you have any reason to disbelieve his dad, gently hint that there might be some profit in his knowing his whereabouts. That would not be dishonest but at least you might know whether to look further and not bother with his family home any more.