Djokovic was never eligible to enter Australia. He lied about having a medical excuse to not be vaccinated. He used 'exemptions' from organisations other than the immigration authorities to muddy the waters. He was trying to blag it all along and got caught.

He got lucky with a border guard making a mistake which ultimately allowed him entry, but doing anything but cancelling his visa would have been contrary to normal treatment under the law.

Now he'll get an automatic 3 year ban, if not more due to the other laws he broke when he entered Australia.