Most paid it little attention. Last Wednesday, when the news broke, the nation was preoccupied with discussing what most considered a far greater outrage: that a reporter had the audacity to ask new Labour Party leader Jacinda Ardern saw motherhood anywhere on her horizon. The Ardern story on stuff.co.nz collected over forty reader comments.

No doubt quite a few read the other article, but not a single reader was interested enough to post a comment, so writing that the news “broke” really is an overstatement. Most likely, readers clicked on the headline after catching the word “rape” and saw that a veteran Napier teacher was convicted of historic rape of an underaged girl. The jury comprised six women and six men, and it took less than an hour to return the verdict. It seemed simple enough. That’s the system we have, and it usually works. Just another pervert caught. Throw away the key. What’s the issue?

Yet this trial tells us something disturbing about what has happened to long-established principles of justice in New Zealand. This case centred on alleged events from 43 years ago and had no evidence, but the jury convicted. In one sense the matter was as straightforward as a coin-toss: the accuser was adamant that the rape happened, and the defendant insisted that it did not. Prosecutor Steve Manning told jurors that there could be no middle ground. He said, “There’s black or white” and the jury had to decide who was lying. He said the fact that the charges were historical made them “no less important to the woman who alleges today that they happened.”

If they happened. I long ago gave up assuming that I knew enough about any trial just by reading about it. A jury almost always knows much more about a case than any casual observer can. Yet in a very important sense the reader knows as much as the jury in this Napier case. It is only a sexual accusation that can come to court with no evidence whatsoever. There were of course no witnesses, and this complainant could provide no details such as dates and times. That means, by definition, that the verdict hinged purely on whether the jurors believed the woman’s account. It therefore comes down to a general question which a detached reader is as entitled to answer as the jury: is a convincing account in itself enough to convict – not just in this case but ever? These jurors clearly thought so. Yet they are wrong. Even if this man is guilty, they are wrong.

He may well be guilty. It’s silly to ask what the odds are, because no one can say. And if he is guilty, it would have been convenient for him to deny everything and count on the absence of evidence to clear him, or prevent the case from coming to court in the first place. Such uncertainty, especially after 43 years, can work in favour of actual rapists.

However, some accusations are false, for a variety of reasons. The complainant may be mentally vulnerable, she may be after some kind of revenge or seek some advantage. Those in the first category are very susceptible to suggestions by counsellors who are convinced that sexual abuse is the source of all their client’s woes. The lawyer I engaged in my own case (which fortunately didn’t come to trial) said that such “true believers” are more convincing in court than those just chasing compensation.

All complaints should of course be investigated with an open mind, but in fairness to the accused it is reasonable to question aspects of the complainant’s story which appear dubious. The alternative is simply to believe, which in effect means the accusation becomes the evidence.

Yet any factors which may once have been used to provide reasonable defence have been repudiated in sexual cases. We may once have cast doubt on a sexual complaint which an accuser takes decades to make, but anyone who suggests that now is said to believe in “rape myths”.

The strongest opprobrium is reserved for anyone who dares to deny that false sexual complaints are rare. Slate columnist Ruth Graham recently referred to such people as “bottom feeders”. Yet false accusations are more common than is usually assumed, and much more frequent than the two percent figure put about by anti-rape campaigners. No one can pretend to know the figures, but a local lawyer with vast experience in such cases told me that most men in jail for historic sexual offences are “probably innocent”.

The prosecutor in the Napier case told the jurors that, in the absence of evidence, they would have to decide which account had “a ring of truth about it.” Is a testimony a performance? We all – men and women – need to ask ourselves whether we consider justice is served when we convict someone because we detect a ring of truth in an accuser’s account.

There was a time when a judge would warn a jury at the outset of a trial not to convict on uncorroborated evidence. Following changes to the Evidence Act introduced specifically to make it easier to obtain convictions in sexual accusations, this no longer applies, and everything depends on whether the complainant can win over a jury.

Our justice system is based on the notion of reasonable doubt. It may be a blunt instrument, but in the face of uncertainty it’s the best we can manage. Convicting on a ring of truth cannot be reconciled with the principle of reasonable doubt.

The convicted teacher has been remanded on bail for sentencing in October, when he will be named and his fate will be revealed. Part of his punishment has come through already: the Teachers Council revoked his authority to teach on the day of his conviction.

There doesn’t need to be a gender war on this issue. False sexual accusations, like sexual crimes themselves, can cast a wide net of misery; not only the victims but also their families can suffer terribly. This is the reason our reaction to a verdict like this one, based on emotion rather than evidence, should cause all of us – men and women – to give such a case more attention than it received last Wednesday.