It turns out there was no hearing and no judgment, simply a consent order lodged by the parties that included the Department of Premier and Cabinet agreeing to orders dismissing its appeal, to setting aside Mr Bluemmel’s ruling, and undertaking to release the documents.
The department thus accepted that two years of arguing that the documents were held by the Office of the Premier but were not minister's documents subject to the Freedom of Information Act had been prompted by an error in processing that no one seems to have noticed until Information Commissioner Bluemmel pointed it out in his decision.
West Australian Newspapers Limited may not have noticed either as it seems to have accepted the matter before the Information Commissioner should be decided on the basis that the documents were held by the Office of the Premier.
As Commissioner Bluemmel pointed out 
under clause 2(4) of the Glossary to the FOI Act, the Office of the Premier is not to be regarded as a separate agency but is to be regarded as part of the Department of the Premier and Cabinet for the purposes of the FOI Act.Ah detail, detail, detail....
71.In this case, the complainant initially made and addressed its access application to the ‘Department of Premier and Cabinet’, not the ‘Office of the Premier. That is, the application was for documents held by the Department of the Premier and Cabinet, not the Office of the Premier. On that basis, I consider it is arguable that the issue of whether the disputed documents are documents of a Minister does not arise, on the basis that the disputed documents are documents of the Department of the Premier and Cabinet and, consequently, are documents of an agency within clause 4(1) of the Glossary to the FOI Act .
All that complex thinking at taxpayer's expense about the impact of the Caretaker Conventions on the operation of government agencies in the pre election period for nothing apparently although the West Australian's report has a spokesperson pointing out that the Supreme Court had not ruled on this issue. Presumably it has been filed away for future reference.
The whole business did delay access to the documents for two years but I'm sure
those behind it wouldn't chalk that up as a partial success.