The accusation, rather, is that certainly Scott Morrison, and perhaps David Hurley, bent or broke the unwritten conventions which underpin what you might think is the tried-and-trusted system of Australian government.

There is a written Australian constitution but it only lays out the bare bones. It doesn't mention the prime minister, for example.

The full constitution is fleshed out by unwritten conventions.

It's about how we are governed. It's not the usual knock-about partisan politics which will come and go (some Liberals have criticised Scott Morrison's secret self-appointments ("unusual, unorthodox and strange", as Tony Abbott put it).

Under the Australian system (which is based on Westminster), parliament is paramount.

The government of the day is answerable to the Senate and the House of Representatives. We, the voters, elect members of parliament and senators, and they hold ministers to account.

This demands that parliament knows what's going on.

Errant - or merely unpopular - ministers may cling like limpets but they can be prised out of their offices - Messrs Tudge ("stood aside") and Porter attest to that.

But the system breaks down if parliament and voters don't know who the ministers are.

In his press conference on Wednesday, Mr Morrison did not address whether he broke the previously accepted convention that parliament should know who ministers are.

He was fluent and defiant but didn't speak to the central accusation.

Parliament does not rule without constraint. The Queen is the head of state and her representative, with her powers in Canberra, is the governor-general.

By convention, he (or just once, she) doesn't have to go along with whatever a prime minister wants (as Gough Whitlam discovered in 1975).

The role of the monarch was explained by the English journalist and legal authority Walter Bagehot in 1867. His view is still accepted in Australia.

"The Sovereign has, under a constitutional monarchy such as ours, three rights - the right to be consulted, the right to encourage, the right to warn."

So Governor-General David Hurley had every constitutional right to "encourage" Prime Minister Scott Morrison to do something or to "warn" him against doing it.

At the beginning of the week, David Hurley looked vulnerable if it had turned out that he hadn't warned Mr Morrison against his secretive ways or urged him to make his ministerial add-ons public.

But he then issued a string of statements (notable in itself - the G-G usually keeps out of matters of controversy).

The clincher was: "It is not the responsibility of the Governor-General to advise the broader ministry or parliament (or public) of administrative changes of this nature. The Governor-General had no reason to believe that appointments would not be communicated."

Constitutional lawyers tend to think this gets the Governor-General off the hook.

"The Governor-General's position is largely bound by convention and he's followed the convention," Kim Rubinstein, professor of law at the University of Canberra, said.

Governors-general can be removed. "The prime minister of the day advises the Queen that he should be removed, and that's the end of it," ANU history professor Frank Bongiorno said.

The prime minister indicated he wasn't going to do that, no doubt choosing words very carefully: "I have no intention of undertaking any criticism of the governor general."

You might think that this isn't a ringing vote of confidence, but it is enough to keep General Hurley in Government House.

Where the constitution is dependent on unwritten conventions, politicians need to obey those conventions even though they are not legally binding. An English constitutional expert called it the "good chap" system - people have to do the right thing.

If the "good chaps" of both genders flout convention, the system breaks down. "A lot of our system is built on constitutional convention," Ryan Goss, constitutional law lecturer at the ANU, says.

"They are rules which people follow because that's what we do. The difficulty is that people say: 'Is it against the law', and if not I'm going to do it."

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Or, as Anne Twomey, a constitutional law professor at the University of Sydney, put it: "A gentleman, a good chap follows the rules of cricket and that's the expectation that there was here. But now that we've seen that that expectation can be defeated, it is probably a good reason to change the system."

Change the system? The unspoken implication is that if the current system based on unwritten convention fails, then a written constitution, with the rules spelt out, may be needed.

When and if the issue of Australia as a republic resurfaces (presumably under King Charles), one of the points of contention will be the powers a president of a Republic of Australia should have.

Should he or she be little more than a rubber-stamp for the government or should the president be able to challenge the prime minister?

In the light of the current controversy, some republicans now argue for stronger powers. "If the hapless GG acted as correctly as his apologists suggest," the author James Boyce Tweeted, "then there is now no option but a republic with defined presidential powers."

In the referendum on a republic in 1999, divisions among republicans over where power should lie helped the monarchist cause. Could it happen again?

The issues raised in the current row will run and run. A can of worms has been opened.