The killer of stop-go worker George Taiaroa had a tendency to go to his guns over the smallest things, court hearings that could not previously be reported were told.
Prosecutors told judges Quinton Paul Winders, 45, had "an apparent tendency on his part to react disproportionately and violently to perceived slights through the use of a firearm".
The hearings were attempts by Winders to have strong evidence against him excluded from the jury in his trial for the murder of Taiaroa.
Instead, the jury heard it all - that Winders shot at people for real or imagined slights; that he was behind the wheel of the vehicle linked to the murder of Taiaroa, 67, of Hamilton on March 19, 2013.
There are often a number of skirmishes in trials before the High Court and the trial that last week found Winders guilty was no different.
In the months leading up to the five-week trial, Winders' lawyer Jonathan Temm tested the prosecution case with hearings in the High Court and - when unsuccessful - the Court of Appeal.
There were challenges to four occurrences the Crown said showed Winders had an over-the-top reaction to events to which he responded with a firearm. In three cases, the firearm was a .22 rifle - the weapon with which Taiaroa was killed.
There were two incidents in 2009 near Whangamomona.
In the first, pig hunter Nigel Ford and three teenagers were shot at as they walked across land neighbouring Winders' property. The other two incidents took place in 2011 and 2012.
The Court of Appeal judgment, which knocked back Temm's objections, endorsed Justice Kit Toogood's finding "beyond reasonable doubt" that the shots had come from Winders' property and "it was highly probable Mr Winders was the shooter".
The court also dismissed the difference between the "cold-blooded execution" of Taiaroa at close range and the more distant shots fired at the witnesses, saying Temm took "too benign a view" of the evidence of his client firing at people.
Instead, the judges said "shooting at or near another person, endangering their safety, is very unusual behaviour". Taking all the incidents together, they said it showed "a disturbing picture of an individual who is prepared to endanger others with firearms for very little reason".
The Court of Appeal endorsed Justice Toogood's finding that the evidence of Winders' propensity for violence over minor issues would counter "a natural inclination on the part of the jury to reject as implausible the asserted motive for the killing".
The motive, which police always said would shock, was Winders' seeking revenge on Taiaroa for a minor crash costing less than $1000 for which he held the road worker responsible. It happened a week before the murder when a vehicle in which Winders was travelling with his father went past Taiaroa's stop-go sign, said to be leaning against a truck on which the road worker was sitting.
"It might be thought a remarkable coincidence that a person with that propensity should only seven days before the murder be involved in an incident with the murder victim for which he appears to have held the murder victim responsible," the appeal court concluded.
Other evidence objected to by Temm but ruled admissible by the Court of Appeal included a montage of photographs from which Winders was picked out by a witness who claimed to see him speeding from the scene in a vehicle linked to the murder.
Also ruled acceptable was a police interview with Winders, during which his story changed under questioning by police.