Some politicians have the memories of goldfish. This month's Supreme Court decision on the Urewera case confirmed what the police have known for years - they do not have the right to use covert video surveillance on private land to obtain evidence.
Chief Justice Sian Elias went further than her fellow judges and caned the cops: "In circumstances where the police officer in charge of the inquiry knew that there was no authority for such filmed surveillance, the deliberate unlawfulness of the police conduct in the covert filming, maintained over many entries and over a period of some 10 months, is destructive of an effective and credible system of justice."
As a result, 13 people arrested in the so-called Tuhoe raids have walked free. But the Supreme Court considered charges against another four were serious enough that, unlawful garnering of evidence notwithstanding, their cases will proceed.
So what has the Government done? It has panicked.
We are told by the Prime Minister, who is advised by Crown Law, there are serious implications for "law and order". Some 40 cases are awaiting trial (not connected with Tuhoe) and "serious criminals would walk free" because evidence has been gathered unlawfully.
That's more than a bit presumptuous. If these accused are indeed so "serious", then surely their evidence can be admitted under the Evidence Act, just like the other accused in the Tuhoe case? The Evidence Act, according to constitutional law specialist Professor Andrew Geddis of Otago University - who has commented at length on this issue on his Pundit blog - gives the courts the discretion to hear unlawfully obtained evidence.
Furthermore, Geddis writes, "just because evidence was unlawfully obtained does not mean that it cannot be relied on in court".
But we can't have an election campaign without the Ma and Pa of New Zealand politicking, Laura Norder and Greg O'Connor, making an appearance. Laura Norder says dangerous criminals are running amok, and Greg O'Connor says the police must enter private property and set up secret video cameras to record activity to prove guilt in court and keep us all safe.
"Jump", Laura Norder shouts and politicians answer, "How high?"
Helen Clark's Labour Government similarly panicked when, in June 2003, the Court of Appeal ruled Maori were entitled to seek customary title to the foreshore and seabed through the Maori Land Court.
Spooked by Don Brash's Orewa rhetoric and manufactured nonsense from chattering classes about Pakeha being denied access to beaches, Labour passed the Foreshore and Seabed Act, a retrospective breach of property rights.
At least it wasn't passed in urgency, but it had - and continues to have - negative consequences for all politicians, including Labour.
But it does seem - for the moment - Labour is pausing over whether it will support National in overruling the Supreme Court's decision.
We all know some police tell lies. In this column I've campaigned hard against National's Criminal Amendment Bill which wanted to do away with the right to silence. Thankfully - by a very slim margin - that freedom is still available to us.
But for how long? The New Zealand Parliament has huge powers, with few checks and balances. Recently much has been written, and said, about this country's increasing lack of respect for the police force. For them to function properly we need to hold them in esteem. But this is not the way to do it.
It is morally wrong that the Government should rush in and ram through a retrospective law, under urgency, to save the butts of the police. Cops have known since the 2007 Law Commission Report their surveillance was legally dodgy.
Now the whole country knows, thanks to the Supreme Court ruling, that some police behave as if they are above the law. They are not. This legislation must, at the very least, go through select committee and be scrutinised by experts. It's nonsense to try to scare us with rhetoric that dangerous criminals will go free unless it is passed in two weeks.
Sure, we need to be protected from dangerous criminals. But just as importantly, we need to be guarded from the enormous powers of the state.