Even under the best of circumstances, the Christopher Deedy case, which ended Monday in a mistrial, would have been difficult to adjudicate. The fatal shooting of Kollin Elderts of Kailua by the federal agent, here in advance of an international conference, followed a chain of events involving bad choices by both men.

However, the criminal justice system did not have to make it even tougher on the jurors by pressing them for an all-or-nothing verdict on a second-degree murder charge in the 2011 incident. The jury was not given the option of a conviction on the lesser offense of manslaughter. It seemed all but inevitable that 12 individuals would struggle to agree that Deedy had "intentionally or knowingly" killed Elderts, as required for a murder conviction, given that self-defense was presented as a mitigating factor.

To their credit, the principals in this criminal-justice drama resisted the popular impulse to strike comparisons between this case and the Trayvon Martin shooting, in which race was frequently noted as an element. The prolonged legal arguments stuck to the basic facts of the case, throughout.

But the hung-jury result surprised few experts watching the case under these circumstances, and it could well recur in a second trial. That’s why it’s critical that Circuit Judge Karen Ahn strongly consider adding the instruction to the next jury to weigh the case for a manslaughter conviction.

Criminal defense attorney David Hayakawa, among others, cited a state Supreme Court ruling that jurors should be allowed to consider the lesser offense when there is a rational basis for it.

These analyses are complex, but such a rational basis seems apparent in the legal definition of manslaughter, which a person commits when he or she "recklessly causes the death of another person." Ahn and prosecutor Janice Futa, though, agreed that there was no evidence supporting a manslaughter conviction.

The fact that both victim and defendant had been drinking could be an issue; intoxication can be a complicating factor in finding recklessness. Still that concern seems outweighed by the evidence that reckless behavior was at hand.

Should Deedy, off-duty in the early-morning hours when he stopped in at McDonalds, have brought his gun along? Being armed and having consumed alcohol, should he have intervened against Elderts in an argument?

The victim in this case was aggressive and combative and the final scuffle for the gun seemed to doom the encounter to this deadly end. But the jury at least deserved the chance to evaluate whether recklessness could have been the force that culminated in Elderts’ death.

Not surprisingly, Brook Hart, Deedy’s attorney, has said he will fight against a retrial being ordered. After certain mistrials, ordering a second trial has been found to place the defendant in double jeopardy, barred by the U.S. Constitution.

Hart said he will argue that there had been no "manifest necessity" for the judge to declare a mistrial, as required. Holding the judge to this standard is essential to curb the state’s capacity for repeated trials — the government certainly has more resources to pursue prosecutions than the accused has to defend himself.

That said, many in the community will conclude that the government should have another go at this case, in the interest of letting justice work its way to a more definitive conclusion.

It’s hard to see how a second jury would be any more likely to reach agreement than the first, unless they are given instructions with enough breadth for a reasoned decision.