Agree Spinex. Having read through the report it appears likely a stall/spin on final because the pilot tried to maintain distance behind a slower aircraft. Coroner appears to be swayed by the references given by people who were not there because of their titles. Coroner could have used independent aviation expert for some sound advice.
The fact that this opened a can of worms for RAAus and the manufacturer is incidental to the crash. No one comes out of this smelling of roses except perhaps the RAAus CFI who did not give the eminent professor an RAAus certificate after 25 hours of training because he was having trouble on approach and landing!