The Final Report into the loss of HMAS Sydney II has been handed down and is available online.
The Report consists of two volumes of evidence and conclusions and a third entitled "Frauds, Comspiracies and Speculations". The website also includes links to transcripts of evidence, some animated recreations of the Sydney- Kormoran action, and appendix and ships' plans. I've not yet read it all (I wonder how many people have) but the Summary looks to be a good overview of the major findings.
Media reporting has tended to focus on the degree of culpability of the Sydney's captain. From what I've read so far the Report, while acknowledging that it was not wise for the cruiser to approach so close to a ship whose identity was unconfirmed, stops short of saying that the captain was negligent.
It's a long time after the event, and many people who lost friends and relatives may be seeking closure rather than retribution. Perhaps they'll be able to draw their own conclusions from reading between the lines of what may not be (given the various matters which the Report dismisses as frauds, conspiracies and speculations) the last word on the topic but should be the most authoritative one.