Experts advised Toa the orca be euthanised but the Department of Conservation kept him alive for almost two weeks, knowing there was a chance he could not be released back into the wild.
A document dump by DoC has revealed some experts repeatedly recommended euthanasia, starting as early as the day after he was found in Plimmerton - but DoC didn't formally consider it until a day before Toa died.
Toa was stranded on July 11 and died 13 days later on July 23.
"If [he is] dependent with no hope of reuniting [euthanasia] would be the most humane option," one unnamed expert said on July 12.
A summary of the international advice given on July 15 - eight days before Toa died - revealed the consensus was he had a "close to zero" chance of survival.
"In my opinion, if you can't care for the calf long term and the Government is unwilling to move it to a facility that can, you should humanly euthanise it sooner than later."
Jack Mace, DoC's director of operations for the lower North Island, says the decision to keep Toa alive was made while he was stable and in good condition, in the hopes he could be reunited with his family.
"That decision [to keep and feed Toa] was made by DoC incident control which cycled through a few different staff but that was a consistent decision - some experts said it would be possible to reunite it with its pod – so the incident controller had to take that range of advice and make a decision."
Mace says orca are critically endangered in Aotearoa, with only 200 of them alive – so DoC was hoping it would be a happy ending.
"We had this very unusual situation where this critically threatened juvenile unweaned animal beached itself but we had this really strong support from experts - albeit with a wide range of opinions - and everyone really pulled together around this challenging situation."
However time stretched on, and multiple searches for Toa's family came back unsuccessful.
As the search went on, costs also crept up. Part of the document dump revealed the total cost of Toa's care totalled $129,780.
The costs reveal $17,446 was spent on travel costs, flights and accommodation for 20 specialist staff to fly in and care for Toa. Site security cost a further $15,871 and meals for staff cost $13,941.
Simply moving Toa from the location he was found in to the holding pen cost $3,863.
Further texts from July 17 – six days before Toa died - revealed the view of international experts brought in to consult was "unanimous" - euthanasia was the best bet.
"International feedback has been unanimous," texts to DoC say.
"I forwarded you an email from [International Fund for Animal Welfare] this morning – from day one she has been saying euthanasia is best."
And DoC was "slowly" moving that way too, according to the texts.
A range of scenarios supplied to the Minister of Conservation on July 22 reveal aside from reuniting him with his family, DoC recognised the best option was to euthanise Toa.
The decision was due to be made on July 23 – but it was never finalised. Mace says morning came, and a decision hadn't been made.
"We had worked through all those scenarios and we wanted to really carefully understand the ramifications of all of those – the next step we had was to socialise it again with the experts, particularly with tangata whenua and then we were going to make a decision, but Toa passed away before that decision was made."
Despite the issues with Toa's rescue, Mace says broadly, DoC would follow the same procedures – although he acknowledged there were "lessons to be learned".
"Although Toa died in the end we kept him stable and sustained while we explored those options as best we could."
Mace says an internal and external review will be conducted into the efforts to save Toa.