The jury is always right. Last week, David Bourke was found guilty by seven men and five women of murdering his wife, Jean Gilbert. After the sentence, he was heard saying to his mother: "I don't believe it."

He wasn't the only one surprised at the verdict. In the course of the trial, judge Barry White made remarks that suggested he thought that 49-year-old Bourke didn't commit murder within the definition of the law.

At a break during the defendant's highly emotional testimony, Judge White addressed prosecuting counsel Isobel Kennedy. "Whoever decided this is murder rather than manslaughter should bring themselves into court." Kennedy replied that that was a matter for the jury. And so it turned out to be.

The case was high profile, and the result appears to have divided public opinion. A number of cases involving men killing their wives have been before the courts in recent years. Anton Mulder, Gary McCrea and, most notoriously, Joe O'Reilly, murdered their wives in 2004. In 2006, Brian Kearney did likewise, although his conviction is under appeal.

Bourke's case differed greatly from all the others.

Bourke stabbed his 46-year-old wife on 28 August, 2007, in front of their three children, at their home in Castleknock in Dublin. Gilbert had just returned from a visit with the new love in her life, Robert Campion.

Two days previously, she and Campion had arrived back in Dublin from England, where Campion lived. He was going to move to Dublin to be with her. The day before the killing, Bourke came home to find two dirty plates in the kitchen and the smell of cigarette smoke. His wife had brought her new love into the family home.

By then, according to medical and anecdotal testimony, Bourke was a wreck. He had been on anti-depressants since soon after his wife told him of the end of their marriage two months previously. He had seen a psychotherapist, who feared for his safety. A neighbour had observed him walking aimlessly in a nearby park.

On the morning of the killing, he said that Gilbert returned with a "smug, self-satisfied" look on her face. He went into the kitchen, picked a knife, secreted it in his trousers, went out to the living room and stabbed her four times.

Immediately afterwards, he rang the emergency services, and claimed he gave his dying wife mouth-to-mouth resuscitation. In interviews, he told gardaí he had wanted to harm her but not kill her.

His main plank of defence was provocation. A successful defence under provocation would reduce the conviction from murder to manslaughter.

While Bourke would in all likelihood still have received a long custodial sentence, it probably wouldn't be life, and he wouldn't be labelled a murderer.

Provocation is a common defence against a murder charge. According to the accepted definition, it would require "a sudden and temporary loss of self-control, rendering the accused so subject to passion as to make him or her for the moment not master of his mind".

The test is subjective. A juror is required to view the circumstances not as he or she might themselves, but attempt to do so through the eyes of the accused.

The potential for a defence of provocation to be left up to a jury appears to have greatly increased since a decision in the Court of Criminal Appeal in 2004.

A new-age traveller, John James Kelly, was appealing a murder conviction on the basis that the jury were not allowed to consider provocation.

Hours before Kelly stabbed Chris Cyballa to death in 1999, the victim had rammed Kelly's car. When they both returned to their camp, Kelly confronted Cyballa, and was further angered by Cyballa laughing sarcastically at him. Kelly stabbed Cyballa with a kitchen knife, killing him.

Provocation requires a "sudden and temporary loss of control". There had been a cooling-off period in between the incident with the car and the stabbing. Yet the Court of Criminal Appeal ruled Kelly was entitled to put forward a defence of provocation. (He was convicted of murder again in the retrial.)

The Kelly ruling was referred to in legal argument during the Bourke trial. Judge White expressed reservations about it, suggesting it implied you now couldn't say "boo to a goose", without that being sufficient to use as provocation.

Despite his reservations about the law, White referred to the level of provocation to which he felt Bourke had been subjected.

"My own personal view is that Mr Bourke had had his nose rubbed in it several times between the Sunday [two days before the killing] and the time this occurred."

Much of the comment around the Bourke case has to do with the extent of provocation to which he was subjected. For some, he was in the throes of a jealous rage, and was acting on his anger.

Others see a man who was at the end of his tether. Over two months, the security had been drained from his life. He was a husband who was, in his own words, "cuckolded". Independent evidence confirmed that his personality had been altered. He gave highly emotional testimony in his own defence. And his wife and her new companion appear, from the evidence, to have rubbed his nose in it in the days before the killing.

The jury made up its mind, and, in law, the jury is hardly ever wrong. Unlike the judge, the jury members are not exposed, week in, week out, to the depravity human behaviour can plumb to. Unlike reporters or bar-stool assessors, the jury is charged with an important function, and is present for every last bit of evidence on display.

The law is a different matter. Bourke is now bracketed, through conviction and sentence, with the likes of Joe O'Reilly, who planned a cold-blooded killing because he regarded his wife as an obstacle to his future life.

Once again, the case for reform of the law is obvious. Dividing all unlawful killings into murder and manslaughter, with the former attracting a mandatory life sentence, can and does impinge on the notion of natural justice. There is no political will to examine the issue.

For Bourke, his hope of a successful appeal largely rests with the court finding that Judge White erred in his conduct of the trial. White is a vastly experienced and highly regarded judge who rarely makes a mistake.

Whatever Bourke's final fate, the real tragedy is the violent untimely death of a young woman and the transformative upheaval in the lives of three children, whose security was brutally snatched away on a cruel August morning.