The Great ISX Performance Share Non Sequitur, page-6

ASX may be right or wrong, but ATO issuing a tax bill about the performance shares doesn't mean that handling of the performance shares was done in compliance with the listing rules - that's the basis of ASX's position
the ATO isn't making any judgement on the validity of the issue of the performance shares, but once they are issued (validly or not), the ASX will tax them
in the past the ATO has sought to tax proceeds of drug dealing, but the dealer was successful in claiming a deduction!!! https://www.theage.com.au/national/drug-dealer-beats-taxman-in-court-20041028-gdyvta.html