If you were trained by CASA (or its predecessors), and you were Licensed by CASA to fly under certain conditions and you were endorsed on certain aircraft, CASA has the duty of care - a bit like road third party.
However, the part you missed was the "Self Administration" words used throughout Australia from the mid '80s for just about all non essential things like sports. The self administrator who sets up something, trains people, makes rules etc. has a duty of care along with their trainers, officials etc.
For about the last 30 years or so in recreational flying where allowed people to build their own aircraft on a hobby basis and fly it cheaply, I would say the 10,000 members have been happy with the system, and produced a reasonal safety history. I don't understand why the constant bitching just goes on and on.