There is a point on which one might have reservations about the reasoning at  of the joint judgment (and concurred by William Young J at ). Disclosure, the judges seem to be saying, is not required when the defendant has independent knowledge of the facts. But the difficulty with this is that disclosure enables the defendant to know how the prosecutor intends to prove the facts needed to establish a prima facie case. It doesn't matter what the defendant knows, it's what the prosecutor knows, and how that knowledge was obtained, and whether it is admissible as evidence, that the defendant needs disclosure of, to challenge the assertion that there is a prima facie case.
It seems obvious that the statutory scheme for extradition where the record of case procedure is used does not meet the requirements of a fair hearing, because of constraints on disclosure of the prosecutor's case and the requirement that courts accept - although on a supposedly "rebuttable" basis - the candour of the prosecutor. You could hardly get a clearer example of the legislature requiring the court to take a biased stance. Yet the majority judges don't accept this. In considering whether the scheme complies with the requirements of natural justice , ,  they - in effect - explain why it doesn't then they say that it does.
If there are questions about the power of the legislature to require courts of justice to act unjustly, resort will be had to the inherent powers of the court to act in the interests of justice. Elias CJ and Glazebrook J seek to advance this principle. The majority refer  to the court's ability to refuse extradition after a "meaningful judicial assessment of whether the evidence is sufficient to meet the threshold of a prima facie case", and the word "meaningful" may, one may speculate, encompass cases where there is a judicial sense that unacceptable unfairness has occurred.
Lord Devlin said something sensible in Connelly v DPP  AC 1254, 1354, which I quoted in an article that, for reasons that now nearly escape me, I called "Criminal Equity"  New Zealand Law Journal 427, a copy of which is available here.