This week, Jo Haylen stepped aside from her role as transport minister in Chris Minns' cabinet. (ABC News: Ethan Rix)
Former Transport Minister Jo Haylen pulled off a political magic trick that left her colleagues in a state of shock and awe.
She managed to drive the Minns government into a ravine without ever getting behind the wheel.
And she did it without breaking any ministerial guidelines. It's no mean feat.
The NSW Transport Minister has managed to drive the Minns government into a ravine. (ABC News: Nick Dole)
You could drive a taxpayer-funded mini-van through the holes in the rule book, which makes no mention of ensuring that trips are work-related.
In fact, it specifically states that personal journeys are permitted.
Nonetheless, when Ms Haylen used a government mini-van and driver to ferry herself, ministerial colleague Rose Jackson and others to a Hunter Valley winery for a long lunch, she broke an unwritten code of cabinet ministers.
Don't embarrass the premier.
Minns risked his own credibility to protect her
Ms Haylen's lapse of judgement was damaging enough, but her explanations left the public and the premier with the impression that it was isolated.
Earlier this week, Ms Haylen apologised for her drive slip-up but stressed she would not resign. (ABC News: Nick Dole)
On Sunday, when asked whether she had ever made a similar decision, she said she couldn't recall doing so.
Perhaps her failure to categorically deny the suggestion should have been a warning about the revelations to come.
NSW premier defends Jo Haylen after more trips emerge
Photo shows Jo Haylen NSW Minister for Transport stands behind microphones at a press conference
On Monday, it emerged she had used drivers to shuttle herself and her children to weekend sporting engagements.
She'd also used a driver to take her family across the Blue Mountains, to visit her chief of staff's house.
However, Ms Haylen privately assured the premier that on both occasions, she was engaging in work, either directly after the excursions, or during them.
On that basis, the premier went on breakfast radio on Tuesday and backed her.
"There's been … a massive, but singular lapse here," he told Nine radio.
"I asked if there were other examples, and the media did too, and I was told that no, the answer's no."
Moments later, host Ben Fordham suggested Ms Haylen had embarked on another winery trip, using a government driver.
The log book showing the 13-hour round-trip on January 25. (Supplied)
Chris Minns did his best to navigate the question, repeating the assurances he'd been given.
"I mean, I checked whether there were other incidents or examples," he said.
"I take her at her word."
The premier had risked political capital to protect Ms Haylen and he appeared to know, in that moment, it was coming back to bite him.
Within a few hours, Jo Haylen had tendered her resignation.
Haylen knew she had to go
Anticipating more embarrassing headlines, Jo Haylen conceded she had become a distraction the government could ill afford.
"My mistakes are now causing the government damage," she told the assembled media.
The scandals Jo Haylen survived before taxpayer driver controversy
Photo shows Jo Haylen NSW Minister for Transport at a press conference
"I did not break the rules, but I acknowledge that's not the only test here.
"I've let the public down and I'm very sorry for that."
She admitted she and her husband had made another Hunter Valley trip last year, but insisted the circumstances were different.
She had been working during that day trip, she said.
What kind of work had she performed? Exactly where had she visited? She declined to say and refused to take questions.
"See you all soon," she said, before walking out the door as some journalists tried in vain to get their questions answered.
It was a sad end to the tenure of one the Minns government's highest-profile and hardest-working ministers.
The dangers of the pub-test
While Jo Haylen's winery excursion in January may be galling to many taxpayers, the fact that it didn't breach any rules exposed just how open-to-interpretation the guidelines are.
Ministers are on call 24/7 and because their personal and public lives often intersect, they are given a huge degree of leeway in their use of government cars and drivers.
Ministers need to read documents, take calls and get briefings while on the road, in private.
Senior politicians also have huge demands on their time, as Opposition Leader Mark Speakman proved on Monday.
NSW Opposition Leader Mark Speakman admitted he has also used a driver for personal reasons, but cleared himself from parrallels to Ms Haylen. (AAP: Bianca De Marchi)
He admitted having sent his driver on dry cleaning errands, which he argued was on the opposite end of the spectrum to a 13-hour round-trip to a winery.
That may be true, but where should politicians draw the line?
On Tuesday, Chris Minns attempted to answer that question.
He decided from now on, the use of drivers will be banned for journeys that are exclusively private.
However, private use will still be allowed if it's "incidental to the discharge of the minister's duties," he said.
The rules are clearer, but still somewhat opaque.
NSW Premier Chris Minns has set his eyes on updating the rules around what a minister may employ a driver for, but that line is still somewhat unclear. (ABC News: Nick Dole)
In the meantime, ministers past and present, from both sides of politics, may well be reflecting on their own use of government drivers.
And with old travel logs now being scrutinised, others could also be subjected to the "pub test" — as in, whether an average voter would find it acceptable.
For their own sakes, they'd better hope they pass.