The former British soldier described his dilemma of whether to turn back for Hillary Dawa or catch up with the rest.

“Do I go back for the Sherpa who’s probably going to rock up and be fine as he has done hundreds of times before, or do I help my fellow climber who’s got no oxygen, frostbite in his fingers, and obviously, you’re never far off hypothermia up there?”

Responding to allegations that the team had left Hillary Dawa behind to die, Thrall said: “It’s really different on Everest, folks. I had one tank of oxygen that’s half empty [by then].

“To try to get back up… would have taken pretty much all of my oxygen. I’m not trying to offload my responsibility. I’m just saying you’ve got to be real.”

In a subsequent interview with BBC Newshour, Thrall said he decided to “turn to the weakest member of the trio”, referring to Chmielewski, with whom he shared his dwindling supply of oxygen as they continued down the mountain amid a severe snowstorm.

The conditions were so bad that Thrall and Chmielewski both recorded farewell messages for their loved ones, thinking they may not make it back alive.

The group took some 38 hours to finally arrive at Base Camp. At this point, they had assumed Hillary Dawa was dead.

“It was a complete whiteout,” Thrall said. “All the ropes were a foot under snow… In none of the time when I looked back up the mountain did I see any sign of Hillary.”

Chmielewski, meanwhile, has also accused HTA of negligence.

“Look, Hillary Dawa was left alone; he rescued himself,” Chmielewski tells the BBC. “This shows the sad truth about how Himalayan Traverse regards its employees. Customers are treated similarly.”

Chmielewski claims that Pasang Kaji Sherpa, the other mountain guide in their group, had notified the company on 30 May that Hillary Dawa was missing, but that no search operation was launched until days later.

Chmielewski, who was also admitted to hospital with frostbite, further suggests that decisions were made haphazardly during the expedition, and that the company appeared unprepared.

“I have huge reservations about the agency that organised this expedition,” he says. “I think they should lose their licence.”

Hillary Dawa maintains he was “forced to stay behind” near Camp 3, which sits about 7,200m above sea level, because he had run out of oxygen and could no longer walk.

Without supplemental oxygen, a fully acclimatised climber would typically survive only two to three days at that altitude.

“I couldn’t walk… I didn’t eat anything for the first two days. Then I began chewing ice, but it pained my teeth,” Hillary Dawa told BBC Nepali from HAMS Hospital in Kathmandu. “I didn’t think I would be alive.”

Then he discovered chocolates in his pocket, and managed to get some melted ice to drink.

He made his way down slowly, only to fall into a crevasse, according to two people who spoke to him about his ordeal.

Then, an avalanche that sent snow tumbling into the crevasse gave him the first hope he had had in days.

“Stepping on the snow, I stood up and looked above… It felt like I could get out from there,” he said.

Once he scrambled out, he found ropes nearby that helped him manoeuvre further down. It was there he saw the cleaning team, the first people he had encountered in almost a week.

Hillary Dawa was transferred from the intensive care unit to a general ward early this week and is “recovering well”, his family tells BBC Nepali.

HTA’s founder and president Dawa Sherpa said that when his company had realised on 30 May that Hillary Dawa was uncontactable, it had notified its partner, 8K Expeditions, the larger expedition company that helped issue Thrall and Chmielewski’s climbing permits.

“The search operation was delayed solely due to adverse weather conditions, but it does not mean there was negligence,” he tells the BBC.

“The weather was really bad, it was a whiteout, meaning we had deep snow continually for a few days. It wouldn’t have been possible to send a helicopter immediately. I would have been sending the rescuers to die.”

Dawa adds that 8K Expeditions should be the company executing the rescue, because they were the ones who issued the permits, but 8K Expeditions maintains it was not responsible for providing the logistics or operational services for this particular expedition.

“Nevertheless, as part of our responsibility and commitment to supporting the mountaineering community, we did our best to assist in the search,” the company’s managing director, Lakpa Sherpa, tells the BBC.

Lakpa confirmed that HTA had indeed made first contact on 30 May, but later fell off the radar. HTA did not respond to these claims.

“We attempted multiple times to contact Himalayan Traverse Adventure for further information and co-ordination,” Lakpa says. “However, they were unreachable… On 2 June, we established contact with Hillary’s family and co-ordinated an aerial search operation.”

That search came up empty.

8K Expeditions has called Hillary Dawa’s ordeal a “true self-rescue” and “nothing short of a miracle”.

Everest experts say camp cooks are rarely equipped to scale the mountain.

“Generally, local guides that take clients to the summit of 8,000m peaks are trained specifically for this purpose,” says Ben Ayers, a longtime Everest reporter for Outside Magazine.

“Hillary Dawa had experience working in this capacity in previous years, but he was late in his career.”

Chmielewski, the Polish climber, says HTA told them Hillary Dawa was re-assigned as a climbing guide “because their original guide had drinking problems and a health problem”.

“We weren’t told exactly what it was,” he tells the BBC.

In a second call with the BBC, HTA manager Angfurba claims the two clients did not want to pay the additional cost for a more experienced guide after their original one was removed.

Thrall and Chmielewski each paid about $37,500 (about £28,000) for the expedition, which includes an attempt up Everest and the 6,189m Island Peak, Angfurba explains.

“They paid one of the cheapest prices and yet they expect VIP service,” he says, adding that other companies charge six-figure sums for similar trips.

Chmielewski dismissed this comment as “absurd and outrageous”. The climbers paid an additional “several thousand dollars” expecting a qualified climbing guide, he says, but Hillary Dawa was put on the job “due to a lack of personnel”.

Angfurba also suggests that Hillary Dawa should have established contact to let the company know he was still alive.

“He had a functioning walkie talkie with extra batteries,” Angfurba says. “It would have taken 10 seconds.”

Hillary Dawa’s family and friends, however, argue that the Sherpa was abandoned. As he recovers in hospital, they demand that justice be served to those accountable.

“I believe this problem occurred because they took him as a cook but used him as a guide,” his longtime friend Pasang Dawa Sherpa told BBC Nepali.

“Our main question is: why wasn’t a search initiated right after he got trapped? We want to know why there was such negligence.”

[BBC]