Jim's death remains unexplained at this time.  The pathologist who examined Jim has been unable to find anything conclusive and we await further tests which we hope will establish what happened, but this may take some time.  However, although there isn't a definitive answer at this time, it appears that Jim had a fall in his flat which led to a heavy nosebleed.  It seems that Jim had made efforts to stem the bleeding and then went to sleep in his bed from which he never woke.  We are consoled in the hope that, after he went to bed, he didn't know too much about it.