Lots of unsubstantiated rumours, no hard facts. A lot of armchair experts around YSBK claim they know the cause but we will all have to wait for the ATSB to complete their investigation.
It always amazes me how quick people are to blame "pilot error" (many of them pilots themselves) when they have no facts (except what they have seen in 20 seconds on Channel 10.)
What is a fact is that Les Morris was an extremely fastidious instructor & testing officer with over 40000 hours experience. He will be sadly missed.