In Fred Hoinville's book 'Halfway to Heaven' he recounts a fatal accident to a VV at Mascot (Sydney's primary airport). Probably in 1944. Curiously it was also witnessed by two men I knew years later. One was Dick Creak who was an apprentice in a maintenance hangar nearby. The other was Lindsay Pryor who was involved with forestry in the war and later became dean of the School of Botany at the Australian National University in Canberra.
The Tocumwal incident, if it did happen, might have been revealed by the only witness to the extraordinary event, the perpetrator himself, on or close to his death bed. A similar thing may have happened long afterwards with a Qantas Catalina in August 1949. This aircraft was blown up in the night at her mooring in Rose Bay, Sydney.
The guilty party was never found, although suspicions abounded at the time, and for years after. A man claiming to have been responsible confessed to his crime shortly before his death in Hong Kong about ten years ago. It cannot be confirmed however. It ranks with all those Bill Tidy FOAF stories. (A friend of a friend.)