Wow. This is a kick to the solar plexus. He couldn't have been much more than 50.
John was an invaluable contributor to the '78 team. He was a heady ball handler, who understood that his role was to play solid D, minimize turnovers, and get the ball to Spanarkel, Gminski, and Banks. His finest hour may have been the FF game that year against Notre Dame when he helped hold off an Irish comeback by making all six of his foul shots down the stretch.
John lost his starting job to Bob Bender in '79 because of his injury and wasn't especially happy about it. He declined to come back for his fifth year in 1980. But most Duke fans prefer to remember him in that halcyon year of 1978 when all things magical seemed possible.
So, yes RIP.