In a court of law, would not discovery produce the required documents? It would be rather foolish of CASA to deliberately withhold this information.
Then again - CASA has done many foolish things in its' tortuous history.
I think the point here is that there's nothing to be "discovered" because there was never any actual documentation to support the action taken by CASA in the first place!
Not always, no. But the High Court has a proud history of producing justice on many occasions... Mabo, overturning Terra Nullius, finding an implied right to freedom of political communication in the constitution, overturning legislation aimed at controlling political advertising or regulating it, overturning a number of visa cancellations by the Minister for Home Au Pairs... there is hope...
And don't forget the famous "Kerrigan decision".