His sudden death was a great shock to his family, friends, and colleagues worldwide.
On leaving school, David completed a 3-year Diploma of Agriculture, followed by 6 years as an overseer or station manager at sheep properties in South Australia and the Western Division of New South Wales. His period at Haddon Rig near Warren, NSW, was to be fateful because it was there that he met the eldest daughter of the Falkiner family, Francis, whom he was later to marry.
At the age of 26, David decided to turn his back on the land and resume his secondary studies so he could gain entrance to University. For a man of 26 to abandon his first calling to embrace the discipline of a return to study, when his girlfriend was performing brilliantly at University, took guts and tremendous determination. David succeeded in gaining a Commonwealth Scholarship and enrolled at the University of Sydney. He completed a bachelor of science with honors in biochemistry, followed by a masters of science degree (at the Childrens Medical Research Foundation) and a doctorate in the Faculty of Veterinary Science at the University of Sydney, which was completed in 1988.