Under the assumption of no afterlife, "John" does not exist after the successful suicide attempt, therefore nothing can be deduced about his state of 'happiness' or 'sadness'; in fact, as libbonobo points out, any such statement is vacuous . HOWEVER, it would be fair to say "he pain that John was in has ended" without making any statements about the current (and vacuous) state of John. As John's life has ended, any pain he is or isn't feeling, based on any existance or nonexistance, is (tautologically) of a wholly different quality.
Even if you assume an afterlife the statement is true, and depending on your beliefs, he may be in more pain, but it is still different pain, ergo, the pain that John was in has ended.
:king: Snow Dog
P.S. got that pain med refill today .