I'm sure there is a lot of still images and video footage taken from all angles that will never be given to the authorities for review.
From what is posted on the web from previous flights, I would be very surprised that no video was taken from inside the cockpit. I am sure that the ATSB would have the wherewithal to recover any video taken.
As for the approvals, if the following is correct reporting of what CASA said, what was the pilot actually approved to do. The following, as normal from CASA, is very ambiguous, or was it intentional by the CASA spokesperson.
"All aircraft operating as part of the air display sought and received approval from the Civil Aviation Safety Authority to do so," CASA said in the statement.
"Under the regulations, except during take-off and landing, or where specifically approved as part of the program of events, the minimum height at which any aircraft may operate is 500 feet above ground level.
"Air displays over built up (suburban) areas, public gatherings and vessels on the surface of a body of water are not normally approved."
Did CASA approved the event overall and then give each pilot specific approval as part of the overall approval?
I did Riverfire in Brisbane a long time ago. The approval from CASA was straight in and out. No turns below 1500 feet except to follow the river.