After going behind his boss' back and leaking Covid patient details, disgraced National MP Hamish Walker had only one option.
And that was to stand-down, says National leader Todd Muller.
"He's done the only thing he could," Muller told Newstalk ZB this morning.
Muller said he had no idea why former party president Michelle Boag sent the patients' details to Walker in the first place. "Maybe the motivations of that might come through the review with Mike Heron QC... we'll see. In terms of why someone in their heart of hearts do these things, only they can answer that."
Walker yesterday announced he wouldn't seek re-election for the Clutha-Southland seat as the party board met to discuss whether to de-select him.
Muller said yesterday: "Ultimately it was a serious error of judgment which cost him his career. His judgment was fundamentally flawed ... and he's paid the ultimate price."
Muller said Walker's decision was "the only thing to do" but said it was "unfortunate" because he'd worked hard for his community.
The leader rejected the suggestion he'd lost control of the National Party.
"Hamish Walker went behind my back and made his own judgment and I'm sure he's ruing it today," Muller said.
Last Thursday night, Walker leaked the details of the then 18 active Covid-19 patients, including their names, dates of birth and which border hotel they tested positive in.
The document included the information of a man receiving care in Auckland City Hospital.
The leak was revealed in the Weekend Herald before Muller and National health spokesman Michael Woodhouse blasted the Government for being incompetent.
Muller got his own legal advice and wrote to the National Party board asking they remove Walker as their candidate for Clutha-Southland as he'd lost confidence in his MP.
Before the result of the board's vote yesterday afternoon, Walker announced he wouldn't stand for re-election.
"I wish to thank the people of Clutha-Southland who I have loved meeting, assisting and representing over the past two and a half years.
"I sincerely apologise for my actions."
Muller said it was "unfortunate" and a tough decision because Walker had worked hard to represent his electorate well.
But ultimately, Walker's actions didn't represent the National Party, its members or supporters, Muller said.
The National Party leader also said in interviews he also thought the actions of Boag, who sent Walker the information, were "appalling".
Five minutes after Walker outed himself, Boag admitted to being his source and claimed the information was sent to her personal email through her role as acting chief executive of the Auckland Rescue Helicopter Trust (ARHT). She resigned from the post in her confession.
But yesterday ARHT chair Simon Tompkins said Boag "never had access to any clinical or patient data".
"ARHT is an integral part of the health system and we are entrusted with information about our patients which is properly protected by protocols which only enable access to those who need this data to care for the patient.
"We have reviewed these protocols and are confident that none of this patient information has been subject to any privacy breach."
Prime Minister Jacinda Ardern said the inquiry would continue to ensure personal and private health information was being appropriately shared.
"I do think we need to give ourselves those assurances that people who receive that information were the right people to receive it.
"What we have an example of here though is someone who has, for political reasons, used people's personal information as a weapon. It is never acceptable in New Zealand."
Ardern called the leak revelations "a wake-up call" that the public expect "much, much more of us".