The legal team for Bernard Collaery says the lawyer's prosecution exposed many problems in national security laws.
A hearing examining whether laws allowing courts to conduct secret trials dealing with national security matters should be changed was told the case was not a good example of how the legislation should properly function.
Mr Collaery and his client, a former intelligence officer known as Witness K, were charged over allegedly leaking classified information about an alleged Australian spying operation in East Timor.
Charges against the lawyer were dropped by the federal government in 2022, following a long and protracted legal fight.
One of the lawyers for Mr Collaery, Kate Harrison, told the hearing the multiple national security issues at the heart of the case exposed issues with the laws.
"It's not as if the issue of national security information could be dealt with and the case move on. It would inevitably arise with each new person giving evidence," she said.
"The case highlighted a number of problematic areas in the legislation, which we thought warranted consideration in this review."
Ms Harrison said despite the legal case being over, there was no outcome on secrecy measures that had been imposed during the four-year period it was running.
"We unfortunately remained subject, as does Bernard, to all of the secrecy restrictions that applied during the case," she said.
Another lawyer for Mr Collaery, Christopher Ward, said while there was a place for the national security laws, changes needed to be made.
"I do not think, personally, that public interest immunity is a sufficient safeguard for both defendants, nor for the legitimate interests of the Commonwealth, who may seek to prosecute or otherwise engage in national security topics," he said.
"The focus of this case, having been as it was the actual nature of allegedly secret material, threw into very stark contrast and relief the problems with the act."
The use of the law has been scrutinised after the case of a former military intelligence officer dubbed Witness J, also known by the pseudonym Alan Johns.
The case only came to light after Witness J launched a court challenge against a prison for tipping off police about a memoir he was writing.
Johns was charged, arraigned, convicted on his plea of guilty, sentenced and served his term, without the public being aware of any of it.
Independent national security legislation monitor Grant Donaldson had been reviewing the effectiveness of the laws over the past two days, and whether they should be changed, or scrapped entirely.
Earlier on Thursday, Law Council of Australia president Luke Murphy said the laws needed to strike a better balance.
"The approach adopted in the NSI act amounts to an unacceptable restriction on the right to a fair and public hearing and the principle of open justice, in favour of the protection of information that may be relevant to national security," he said.
