A Czech couple's ''goal-focused mentality'' led them to ignore advice about walking the Routeburn Track in winter, and to make a series of poor decisions as they encountered increasing difficulties, a coroner has found.
Ondrej Petr (27) died near Lake Mackenzie on July 28, 2016, after he and partner Pavlina Pizova became disoriented in bad weather.
In her finding, released yesterday, coroner Anna Tutton concluded Mr Petr probably died of hypothermia as a result of subzero temperatures, inadequate clothing and equipment, and severe fatigue.
Deciding not to notify anyone of their plans in order to avoid paying for the use of huts, they set off from the Routeburn Shelter, near Glenorchy, on July 26.
They intended to complete a 60km circuit of the Routeburn and Caples Tracks, in the Fiordland and Mount Aspiring National Parks, a route that normally takes about six days in summer conditions.
After spending the first night in the Routeburn Falls Hut, they were attempting to reach the Lake Mackenzie Hut when they were caught out by darkness.
After ''going in circles'' in fog, low visibility and high winds, they spent the night in their sleeping bags and wrapped in a tarpaulin.
In the morning, they were soaked through because of heavy snow, and Mr Petr showed the first signs of hypothermia.
But the weather was clear and they could see Lake Mackenzie Hut ''very close'', so set off without eating or drinking.
Leaving the marked track, which appeared steep and covered in deep snow, they decided on a ''short cut'' down the mountainside, but became disoriented and ended up travelling in the wrong direction.
As the weather deteriorated, they could not find their way back to the track, and Mr Petr's behaviour and speech became increasingly irrational.
They continued searching for the track after it became dark, and after a slip Mr Petr ''became frustrated, and yelled at her 'it's all buggered'.''
Later, Ms Pizova noticed his ''voice sounded different, he was 'talking weird stuff' that she could not understand, and was biting wood''.
After they were caught in a small avalanche, she found him wedged between branches and rocks. Exhausted, she was unable to move him, and he became increasingly stuck as he struggled to free himself, weighed down by his saturated pack.
He began gasping for breath, and eventually stopped breathing and died.
After spending the rest of the night with him, she tried to reach the hut the next day, but again became lost and spent a third night in the open in bad weather.
She reached the Lake Mackenzie hut complex early the next afternoon, and broke into the warden's hut, where there was food and blankets.
On August 24, after spending 24 days alone, she was rescued by a searching helicopter after the Czech honorary consul, noticing social media posts by relatives expressing concern, raised the alarm.
Mr Petr's body was recovered by police and LandSAR volunteers two days later, on a steep mountainside, near Ocean Peak, about 2km from the hut.
A New Zealand Mountain Safety Council report on the tragedy said the couple incorrectly believed the weather forecast would be fine for the first few days of the tramp, when in fact subzero temperatures, gale-force winds and snow were forecast for the Harris Saddle, the tramp's highest point.
Mr Petr did not have a waterproof jacket, neither had waterproof overpants, and they lacked winter tramping equipment such as crampons, snowshoes, an ice axe, avalanche transceiver and probe, a snow shovel, personal locater beacon, a map and compass.
The report's authors said there had been ''many opportunities to make decisions that almost certainly would have led to a different outcome''.
The couple could have turned back to the Routeburn Falls Hut on the second day after encountering deep snow, or stayed overnight at the Harris Shelter and re-evaluated their plan in the morning.
Carrying bivvy bags or an alpine tent would have enabled them to keep drier and warmer at night.
When Mr Petr's hypothermia symptoms became severe, Ms Pizova should have given up trying to reach the Lake Mackenzie Hut, and instead focused on finding shelter, getting him warm and giving him something to eat and drink, the report said.
