There can surely be few more horrifying scenarios: a father shooting dead his own son while on a fun hunting outing with family and friends.

A young life taken too soon, a family's life turned upside down, a life sentence of guilt and grief for the perpetrator.

Such suffering is one reason Invercargill Judge Bernadette Farnan decided not to convict Stephen Phillip Long over the death of his son, Samuel (24), on Stewart Island in March.

Mr Long had earlier pleaded guilty to carelessly using a firearm causing death.

The court heard the ''experienced'' hunter on the ''meticulously well-planned'' trip had been unsure about his target and had spent some time before finally taking the shot, believing it was a deer in his sights.

Mr Long's counsel, John Fraser likened the case to that of the Wanganui woman who in June was discharged without conviction after she admitted the manslaughter of her child, whom she left in a car in a car park.

Being on ''autopilot'' was mentioned as a similarity. Judge Farnan saw analogies with that case and took into account Mr Long's trauma, remorse, good character, experience, clean hunting record and the impact of a conviction.

Mr Fraser hailed the decision as ''bold'', ''courageous'' and ''appropriate''.

It is certainly bold, being unprecedented in terms of the charge. Putting emotions aside however, the precedent is worrying.

The argument about the impact of a conviction is often used for high-profile names, sportspeople or students, when others are often not afforded the same advantage.

Where is the evidence a conviction would really hamper them irrevocably?

People may be able to get dispensations to travel.

Employers are surely also able to use discretion and take into account the context of a conviction.

But, if not, is it unreasonable to expect there to be some price to pay for one's actions?

Is the Wanganui case really comparable?

Surely, when a hunter is heading into the bush with a weapon designed to kill, and the intent to kill, the threshold of responsibility is higher?

Those who hold a firearms licence are aware of the rules, responsibilities, and well-publicised risk of human fatalities.

If a person is killed, the cardinal rule of hunting - ''identify your target'' - has been broken.

The fact ''autopilot'' or ''brain fade'' could be reasons, or ''cognitive bias'' (whereby a hunter sees a deer because they expect to see a deer) a common hunting reality, is huge cause for concern.

Trigger happy and trigger blind? Clearly a recipe for disaster.

The decision is undoubtedly compassionate given the heartbreaking circumstances, but true courage is needed, including from the hunting community.

More still needs to be done to stamp out complacency, and honesty is also required.

If the risks cannot be mitigated because of a recognised syndrome that causes mental impairment, gun ownership laws will need to be rethought.

Protection must be at the heart of the matter, and part of the means to achieve that is through sentencing that sends an appropriate message.

A conviction would have done that.

A sentence would not have to be punitive at all, given the self-inflicted torment.

But the last thing needed is another message of firearms complacency.

There are other cases, such as on the road, in which a moment's mistake causes death.

Is a conviction less warranted there also?

And because the dead person is a family member should the treatment be different?

How then do we treat domestic violence and child abuse cases?

Two things are certain. The case is tragic and the decision is divisive.

Given the precedence, the Crown may decide to appeal.

It would sadly mean a further trial for the family, but it may be necessary in the best interests of the country.