The key thing to note about his casualty listing
http://www.flightglobal.com/pdfarchi...?search=346032
is that he 'Died on Active Service', he was not 'Killed on Active Service'. The distinction between the two would be that the DOAS is generally associated with someone dying from
Natural Cause
a car/bike/trusk/ accident
Someone who died when their home was bombed in a bombing raid.
It should not be associated with someone killed in a plane crash, for example someone in a training aircraft or someone getting a lift in a service aircraft.
You can get the reference numbers to get his death cert here:
manxbmd.com/