The Government is also permitting the Urewera accused - against whom charges have been dropped - to keep the fruits of their victory, consistent with the constitutional convention that Parliament should not usurp the role of the courts and decide the guilt or innocence of individual citizens.
There are, however, five key factors which make this a hard case.
First, the details given about the Government's proposed law change may result in the conviction of defendants who should be acquitted because the evidence against them was otherwise unlawfully obtained.
This breaches the doctrine of the rule of law because Parliament is effectively going back in time and freezing the law as it was before the Supreme Court judgment came out. This changes the rules after the fact, mitigated only by the promise of a one-year sunset clause on the legislation.
Second, the Government's proposed change to the law will retrospectively validate illegal conduct by the police. The court found the breach of section 21 in the collection of that evidence was so serious (the police were either reckless as to whether their actions were lawful or they carried out covert surveillance knowing it was unlawful) that the evidence could not be used to prosecute 11 of the accused. This is despite section 30 of the Evidence Act, allowing improperly obtained evidence to be relied on in criminal proceedings when a quite low threshold is met.
Third, the Government's intended response is now to be enacted during the last two sitting weeks of Parliament, under urgency, which is unlikely to allow any public input.
Fourth, the unlawful conduct breached fundamental rights and freedoms in the Bill of Rights, characterised by the Chief Justice as "security against unreasonable intrusion by state agencies into the personal space within which freedom to be private is recognised as an aspect of human dignity".
But New Zealand has no supreme law saying that Parliament cannot pass laws inconsistent with the Bill of Rights Act, which is only ordinary legislation. Thus, the only sanction for the current Government in this instance is political.
Finally, it is difficult to argue that this issue has crept up on the Government. Concerns about covert surveillance were raised in cases and by the Law Commission in 2007. The Search and Surveillance Bill includes provision for warrants but the bill has spent years on Parliament's Order Paper and still awaits a second reading.
No one wants to let criminal offenders get off scot free, but if the Government passed prospective, rather than retrospective, legislation concerning the Supreme Court decision, this would preserve the fundamental constitutional principle that we are all ruled by law (including the police) and we should know what the law and its consequences are before we act.