In a nutshell, the High Court case is about what discretion...

In a nutshell, the High Court case is about what discretion appeals courts have when they find a decision of a lower court to be infected by apprehended bias. Lawyers for Oaky Coal Action Alliance argue that the appeals court has no discretion and must invalidate the decision of the lower court in its entirety. New Hope argues the appeals court has discretion to issue a range of remedies in the interests of justice. These issues are relevant because the QLD Court of Appeal found in favour of New Hope when it determined apprehended bias but did not invalidate the entire decision because that was not in the interests of New Hope (ie would produce an unjust result). But the QLD Court of Appeal didn't exactly spell out its reasoning around that point