It was a headache that came three weeks into the job and added about $30 million to the overall build cost.
"I had to lead through a really challenging environment that should never have been placed on an organisation like us," says Teirney.
"Our goal is to get people into great jobs - you really don't need something like that."
Several years on, Teirney says the organisation is back on a financially stable footing, thanks in part to the team she has gathered around her, who aren't just a bunch of number-crunchers.
"It's not just about producing sets of historic data, it's about helping people make the right investment choices [and] respond to environmental issues that occur."
While the number of women graduating from accounting degrees now equals the number of men, Teirney says female CFOs are still thin on the ground.
She has always worked in male-dominated environments - first at chartered accounting firm Staples Rodway, then packaging company Amcor Kiwi - and says she was always promoted quickly against her male colleagues.
"I guess for me I never experienced glass ceilings, I never experienced roadblocks. Some of the males I worked with were some of my biggest supporters. And if I needed a little bit more of a push and a little bit of courage they were always the ones.
"I had some really good sponsors."
Teirney says Amcor Kiwi was a tough, fast-paced environment, but she began to hanker for a role that blended organisational transformation with a wider social benefit.
That saw her switch to the Auckland District Health Board, before heading out on her own as a consultant when her twin boys, now 12 years old, were little.
The decision was driven by the special needs of her children - one has mild autism and the other mild learning difficulties - but also a frustration with the lack of part-time senior finance roles.
She says genuine flexibility is a challenge a lot of organisations still need to face.
"I actually don't think it's just a female issue where I work now.
"I have a number of males who need equally as much flexibility for health issues or their own families, so I think until we can really crack the business model it is actually quite hard for some people.
"People with children just have that extra battle, that extra burden, and it's just much easier to not put yourself in the ring for a bigger job."
She says it can be a vulnerable time for women when they become mothers, and support and coaching are needed to help them manage through that period.
Teirney says many women are not so motivated by money, either, with a lot preferring a great learning opportunity over financial rewards.
"You've got to make sure these roles are inspiring.
"Also it's important to role model and actually make people have that work-life balance.
"Sometimes it almost becomes a bit of a badge of honour that you're there till midnight and that's actually not right."
Teirney is now adding corporate governance to her CV, after this year joining the board of ME/CFS Support Auckland, a charity that helps people with chronic fatigue, and becoming the 7000th member of the Institute of Directors.
She says people tend to favour the boards of high-profile organisations but she has chosen the challenge and rewards of a role with a newly established charity with limited resources.
"I'm almost a little bit of a change and chaos junkie, really, so I don't go to environments where I'm just ticking along doing business as usual."
Her ambition is to expand her portfolio of boards, particularly in the not-for-profit sector, and gain exposure to a number of sectors.
On the work front, she took over as director of operations at MIT almost 12 months ago.
"My goal is to have a broader leadership mandate than just being a finance professional.
"That will still be the heart of who I am but I want broader skill sets, broader general management experience."
