If Australia makes it illegal to re-identify information, what about information that has been re-identified outside Australia then distributed into Australia?
He was a lawyer, so would be quite aware of the meaning of the words he was uttering.
Sure he was a lawyer and banker and probably never should have been involved with things like encryption and the NBN, but that's politics for you.
The letter sent to the university [0], claims that re-identifying information is actually illegal, according to the department's understanding. (Nevermind that they also admit that particular law is completely irrelevant to the work of the researcher).
[0] https://www.righttoknow.org.au/request/correspondence_on_re_...
Anyone wanting to abuse the information (i.e. a criminal) would not really care to commit a crime by reidentifying so this law would only prevent people who want to help from doing so.
In the end the are always intelligent criminals (or foreign countries acting against your country for their interest). So you will always be able to buy deanonymized data on the black market. Even more the people doing it for that reason can include leaked/stolen datasets to do deanonymization invested if just public data making it potentially much easier.