It is not the purpose of the criminal law to punish the guilty at all
costs. It is not that that end may justify whatever means may have been
adopted. There are two related aspects of the public interest which bear on
this. The first is that the public interest in the due administration of
justice necessarily extends to ensuring that the Court's processes are used
fairly by State and citizen alike. And the due administration of justice is a
continuous process, not confined to the determination of the particular case.
It follows that in exercising its inherent jurisdiction the Court is
protecting its ability to function as a Court of law in the future as in the
case before it. This leads on to the second aspect of the public interest
which is in the maintenance of public confidence in the administration of
justice. It is contrary to the public interest to allow that confidence to be
eroded by a concern that the Court's processes may lend themselves to
oppression and injustice.
....
The justification for staying a prosecution is that the Court is obliged
to take that extreme step in order to protect its own processes from abuse.
It does so in order to prevent the criminal processes from being used for
purposes alien to the administration of criminal justice under law. It may
intervene in this way if it concludes from the conduct of the prosecutor ...
that the Court processes are being employed for ulterior purposes or in
such a way ... as to cause improper vexation and oppression. The yardstick
is not simply fairness to the particular accused. It is not whether the
initiation and continuation of the particular process seems in the
circumstances to be unfair to him. That may be an important consideration. But the focus is on the misuse of the Court process by those responsible for law enforcement. It is whether the continuation of the prosecution is
inconsistent with the recognised purposes of the administration of
criminal justice and so constitutes an abuse of the process of the Court.[125]