You're writing something absolutely incoherent. I just went through your writing proposition by proposition and tore it to shreds and I'll do it again.
"Regarding border entry the Australian government had multiple conflicting positions. "
You're telling me now that TA didn't have a role in border entry according to you? Fine, then it's even more clear; the agency which does govern and which no one disputed governs should be contacted and one should comply with its requirements.
Djokovic's team did not do that. There is no 'reneging' on a position. In the event of doubt, you contact the governing agency. Rules and regulations must be published and supported in writing. This is a basic principle. So basic in fact that if you're denying this, you're basically telling me you've never even opened a textbook on administrative law much less examined actual cases.
All Djokovic would have needed would be a simple letter from the federal agency governing the border stating what it is that his team suggests that they understood as an exemption.
Ask yourself why they did not do this. Even a legal intern would have known to do this.
The federal government had already stated their position. They would be leaving the adjudication to the Victorians for arrivals in Victoria as they had for the last two years. Djokovic believed them when time revealed he should not have. The Australian national government weren't rejecting unvaccinated arrivals before Djokovic. Multiple people gained entry for the Australian Open on the Victorian exemption. The Australian government subsequently moved against those people to keep the fig leaf of consistency.