Hi there, chiming in.
The article refers to a submission made by Hayne's barrister during the appeal hearing that instead of ordering a re-trial the Court of Appeal could make a directed verdict of acquittal. The Court of Appeal apparently rejected that submission given that they have remitted the matter for a re-hearing in the District Court.
It will now be a matter for the DPP to consider whether it is justifiable in the public interest to go a third time. If there had been a hung jury second time around, it is likely that the DPP would adopt the same approach as in the JDB trial and determine that it was not in the public interest. In circumstances where they got a verdict of guilt second time around, that may encourage them to run it again.