SCIDUA and their right to be privileged from subpoena

The Special Committee Investigating Deaths Under Anaesthesia (SCIDUA) is an expert committee appointed by the Minister for Health under Section 20 of the NSW Health Administration Act 1982.
Established in 1960, the SCIDUA is the longest serving committee of its kind in the world, and has contributed to the impressive reduction in mortality attributable to anaesthesia in Australia.
Since its inception, SCIDUA has received notification of more than 10,000 deaths. In the overwhelming majority of these cases (approximately 95%), investigations reveal that the death was not in any way attributable to the anaesthesia.

The SCIDUA Committee
The Committee is known as the Special Committee Investigating Deaths Under Anaesthesia (SCIDUA) and is an expert committee appointed by the Minister for Health. Its Terms of Reference PDF ~12kb are to subject all deaths occurring while under, as a result of, or within 24 hours after the administration of anaesthesia to peer review so as to identify any areas of clinical management where alternative methods could have led to a more favourable result.

The Committee's documents are privileged from subpoena under Section 23 of the NSW Health Administration Act 1982 DOC ~34kb. Confidentiality of all communications between the reporting anaesthetist and the Committee is paramount

"In other words, they investigate deaths under anaesthesia, get the story from the anaethesist involved, BUT THEY ARE PRIVILEGED FROM SUBPOENA? WHY? Can anyone answer this question. I have one very strong possibility - to prevent LAWSUITS. "