One of the great things about replacing the Privy Council with our own Supreme Court is that we get a lot more interesting decisions issued. This week alone has seen three.

It's time to turn attention back to our Supreme Court for the right reasons - the decisions it is releasing. Because this week has seen a couple of pretty high profile judgments issued, along with an agreement to hear a case that likely will cause more sparks to fly in the future.

The first judgment is the Court's unanimous decision that George Gwaze must be retried for the rape and murder of his young niece, even though he was acquitted on these charges back in 2008. As far as anyone seems to know, it's the first time in New Zealand that a retrial has been ordered following an acquittal for murder (as opposed to a conviction, which happens reasonably frequently).

Although that fact makes the case notable, the legal issues involved were novel rather than particularly complicated. The problem was that very late in Mr Gwaze's original trial, a South African doctor proffered new (and potentially extraordinarily important) advice suggesting the little girl's death likely resulted from natural causes. This information was "hearsay", in that an expert witness who already had testified in the case reported hearing the doctor's general statements about allegedly similar cases of natural deaths occurring in South Africa. The South African doctor was understandably unwilling to give a specific opinion on the immediate case without time to study it in depth, but the judge (for equally understandable reasons) was unwilling to delay the trial for the two weeks needed to permit this to take place. So the judge decided to allow the jury to hear a report of the doctor's general information as uncontested hearsay evidence, following which the jury acquitted Mr Gwaze.

However, at the time the Crown reserved the right to appeal the judge's decision to allow the hearsay evidence into court. In both the Court of Appeal and the Supreme Court, every judge agreed that the trial judge made a mistake by allowing the evidence to be put before the jury.

(That said, you can sympathise with the judge at trial. The evidence was potentially so important that to allow the jury to decide Mr Gwaze's fate without hearing it could have turned out to be equally wrong. The fact that the South African doctor later revised the earlier reported information and concluded the New Zealand case was different to those he had seen in South Africa no doubt made it far easier for the higher courts to decide his original views should never have been aired at trial!)

However, the Court of Appeal had split over what should be done with regard to this mistake. Two judges felt that even though the evidence should never have been heard, and even though this error meant the trial process was flawed, it still would be wrong to overturn a jury's verdict of not guilty and require Mr Gwaze to stand trial again after an acquittal had been entered. The dissenting judge thought that the error was so significant that it rendered the trial and its verdict unjust, so a retrial ought to be held.

The five members of the Supreme Court have now agreed with the dissenting judge. Trials are, after all, an effort to create as fair a process as humanly possible to identify the wicked, whilst ensuring that the innocent are not wrongly punished. Even though we place a premium on the latter goal - the presumption of innocence, rules of evidence that exclude prejudicial matters about the accused, and so on - the former goal also is of great societal importance. And so where a judicial error effectively makes it impossible for a jury to accurately determine whether the accused is guilty of murdering a young girl, then there is a societal interest in revisiting the matter through a new trial. Which was the case here; given that the South African doctor's unchallenged (but mistaken) evidence was that the little girl likely died of the same natural causes he had previously seen, there is no way a jury could ever have convicted Mr Gwaze of murdering her.

The second decision hasn't yet made it on to the newspaper websites, although David Farrar has been quick off the mark in commenting upon it. It involves one Mr Siemer, who has been engaged in a lengthy and torturous set of legal proceedings that I'm not even going to attempt to summarise here. The particular sub-issue in this saga to reach the Supreme Court stemmed from a finding that Mr Siemer's refusal to remove defamatory material from various websites he controls constituted a contempt of court. He was sentenced to 6 months imprisonment for his contempt, with the proviso that he would be released sooner if he removed the material as he had been told to do.

Imprisonment as the result of a contempt of court is neither unusual or particularly problematic - it is obvious that if a court is to be able to do its job, it must possess the power to force people to do what it says. What brought Mr Siemer's case to the Supreme Court, however, was the potential length of the sentence he was to serve. You see, an alleged contempt of court is tried by a judge alone, with no fixed penalty attached (because contempt of court has its basis in the common law, not statute). Yet the New Zealand Bill of Rights Act 1990 (NZBORA), s.24(e) states that every person charged with an offence; "Shall have the right ... to the benefit of a trial by jury when the penalty for the offence is or includes imprisonment for more than 3 months". So, can the courts use a common law power to jail someone for 6 months for contempt of court without a jury trial, in spite of the legislature's express guarantee of this right?

By a bare majority, the Supreme Court has decided that the courts cannot do so. All five judges agreed that contempt of court is an "offence", and that to punish a contempt with a sentence of more than 3 months infringes the right guaranteed by s.24(e). Two members of the Court (Elias CJ and McGrath J) nevertheless believed that this infringement could be justified under s.5 of the NZBORA: "The common law summary procedure [i.e. judge only trial] remains the only means yet identified which enables effective protection to be given to the threats to the rule of law that all contempts provide.  The unusual nature of the procedure emphasises the gravity of the threat to the administration of justice and in the eyes of the court.  The procedure also adequately protects persons who come before the court." Consequently, they would have upheld the lower courts' decision with respect to Mr Siemer.

However, three members of the Court (Blanchard, Wilson and Anderson JJ) disagreed with this conclusion. They thought that the NZBORA guaranteed right trumped any historical common law power to punish contempts: "Imprisonment has been marked out as the severest punishment which can be imposed.  Parliament has declared in s 24(e) that only in the case of a charge where any imprisonment can never exceed three months will the fundamental right of jury trial be denied.  ... The Court ought not, in our view, now to create by recourse to s 5 [an] exception to s 24(e) for what has been called a “common law offence” and for which no maximum punishment at all is prescribed by statute or by the common law itself." Consequently, they reduced Mr Siemer's maximum time in jail to three months.

But before getting too carried away with Mr Siemer's victory against the system, we should note that unless he does what the courts have ordered him to do and takes down the defamatory material by Thursday, then he's going to jail. Furthermore, if he still hasn't taken it down in three months time, that will constitute a new contempt - so opening him to another 3 month stint in jail. And finally, what will happen if Justice Minister Simon Power goes through with his proposal to raise the threshold at which a right to jury trial kicks in to three years? Assuming this will involve an amendment to the NZBORA, s.24(e), will this then increase the potential punishment of future contempts up to three years?

The last move by the Supreme Court this week is to set up a fascinating decision for the future. It has agreed to hear an appeal in the case of Valarie Morse, the protester who in 2007 marked the Wellington ANZAC day celebrations by burning a New Zealand flag. Her actions were deemed to be offensive behaviour in the District and High Courts, a conclusion upheld by a split Court of Appeal. I don't know which way the Supreme Court will go on this case, but given that its last attempt to determine the legal boundary for antisocial protesters resulted in a 3-2 split court and a 108 page decision, I suspect it doesn't know itself.