I've got to be honest, having spent the last 48 hours listening to the whole season of the Trace podcast and reading through the Inquest findings, this very much feels like one of both of the priests, Father Bongiorno and Father O'Keeffe, are very much the guilty party/parties but there's yet to be enough evidence put together to convict.
These two had the motive, means and opportunity and have probably gotten lucky that years of either sub-standard police work or a desire not to throw shade at the Catholic Church amongst senior police (Victoria Police have form for this...) meant the window of opportunity for nailing them in an airtight case was lost.