On the afternoon of February 17, 2018, Goldfinch was at the golf centre with his partner and others celebrating a friend's birthday.
The group paid to play nine holes of golf and had brought their own beers, which they were carrying in chilly bins.
"There were about 15 of them playing, so before they teed off at the first hole they discussed how they needed to be careful about where they hit the ball and where they stood," said Coroner Johnson.
Goldfinch was helped to a car and driven to the Lakes District Hospital Emergency Department.
"At first, Jaden was screaming and clutching his head. He then started to drift in and out of consciousness," said Coroner Johnson.
"(His partner) tried to keep him awake by rubbing his arms.
"They arrived at the hospital within five minutes and Jaden began having a seizure as he was being taken inside."
Goldfinch was admitted to hospital and the doctor on duty ascertained he had a severe traumatic brain injury and needed to be treated in an intensive care unit.
After consulting with an ICU consultant at Dunedin Hospital the doctor intubated Goldfinch and put him on a ventilator.
He was given medication to reduce the raised pressure inside his skull, to manage his agitation and to both sedate him and relax his muscles.
He was then transferred to Dunedin Hospital by helicopter and admitted to the ICU under the care of a neurosurgeon.
Goldfinch was given a CT scan which showed brain injuries, including a large acute subdural haemorrhage with formation of a pool of blood which was between his brain and the dura, the brain's outermost covering.
The neurosurgeon reported that this was due to rupture of an artery and was consistent with the impact from the golf ball.
"Jaden was taken straight to the operating theatre where he underwent a decompression craniectomy in which a portion of skull bone is removed to ease pressure on the brain," said Coroner Johnson.
"It also allowed the brain to be accessed so that the haematoma could be removed.
"Jaden was then taken to the ICU. Both his pupils were dilated and not responding to light.
"Despite being given maximal active treatment over the following four days, Jaden died at 5pm on February 21, 2018."
Coroner Johnson said while the cause of Goldfinch's death was clear it "required further investigation".
Police provided a thorough report on the death to her and said they were satisfied that there was no criminal liability or suspicious circumstances surrounding Goldfinch's death.
She said authorities were not made aware that the group were drinking alcohol when the incident happened - until after Goldfinch died.
That meant it was "therefore impossible" to know whether or to what extent the judgement of Goldfinch or King had been affected at the time.
"It is also entirely foreseeable that balls do not always travel straight ahead as planned; an unintended slice - as happened - can send a ball in an entirely different direction.
"I therefore find that Ashley was partly responsible for Jaden's death by his deliberate action in hitting the ball in the direction of three people, with no regard for whether it might not go where he intended it and hit someone.
"I am satisfied that Ashley's action contributed to Jaden's death."
Coroner Johnson said three of the group who went in to the trees "took care" not to walk in front of the others who were progressing down.
"But Jaden moved ahead of them and then went behind a tree. By doing that he would not be able to see what was happening on the fairway," she said.
"Jaden was already risking being hit by a ball by being at the side of the fairway forward of players on it.
"By going behind a tree, so that he could not see what was happening on the fairway, and then suddenly coming out from behind that tree, his risk of being hit by any stray ball Increased.
"I therefore find that Jaden was partly instrumental in his own death and therefore contributed to it, although it was nowhere near as significant a contribution as I have found Ashley's to be."
Coroner Johnson did not make any recommendations to prevent further deaths.
"My inquiry is now concluded," she said.
"I extend my condolences to Jaden's family and his friends and apologise for the length of time it has taken to conclude my inquiry."