We do know it hasn't happened here or anywhere else.
The term “advice”, if this becomes the basis of a report, should be adjusted here. The term “advice” in the normal sense is not what we're talking about here; “advice” in the constitutional sense.
We maintain the fiction that the Governor General, or in Britain the Queen, is the absolute monarch and dictator of the country, but receives advice from a variety of ministers. The reality is that when we say “advice”, we mean “instructions”: you will do the following, or I'm telling you to prorogue the House, or I'm telling you to appoint this person to the Senate, etc.
That kind of advice is only given by the Prime Minister. It's the most fundamental of our conventions, dating back to the early 1700s. Before then the King used to have multiple advisers and would call upon one to deal with this issue and one to deal with that issue. But the convention is that one person--who is known as the Prime Minister, and that's in itself a conventional term--offers all the advice and is the only one who actually advises the monarch.
And refusal to accept advice, any advice, effectively means that the Prime Minister has been fired. So if the Prime Minister says, “I advise you to prorogue” and the Governor General says “No”, what the Governor General has also said is, “And you're fired. You're not my Prime Minister anymore”.
So when we say “advice”, I think we should say “advice in the conventional sense”, or find some way of wording it so that it's clear that's what's meant.
The other kind of advice, what we mean when we think of advice in the normal sense, is what's referred to here as “informal advice” and that is so the Governor General has at his or her disposal, at the time, a variety of people. And we don't know who they all are, but we do know that at different times Professor Hogg and Professor Monahan have been used, and others. They actually provide advice in the sense of, “Here's what I think about whether or not you should accept the recommendation of the Prime Minister, understanding that if you do accept it, this happens, and if you don't accept it, you're effectively dismissing the Prime Minister”, and so on.
So there are two clear concepts for which one word has been used, unfortunately.