"I do wish we could get away from this blame - who's fault it is. If we could just get that and say 'It is what it is and what can we each do about it?'
"Collectively we have to do something different because what we are doing at the minute isn't working. The issue is, why is that the case."
While some, including Flavell, congratulated her on her straight talking, teacher unions NZEI and PPTA interpreted it as an attack on teachers.
John Minto's Quality Public Education Coalition called for her resignation, saying she had been brought in from the poorly performing British system "to implement its failed policies here".
Ms Longstone moved to New Zealand to take the job about a year ago. She had been to New Zealand once before - in 1999 to see a cousin in Auckland - although she has a distant connection with Wellington.
One of her grandfathers came to New Zealand in the 1920s and sent for his betrothed, whom he married in Wellington. The couple lived in Napier but, after the 1931 earthquake, they returned home to Sheffield.
She left two of her older children in Britain at university. She lives with her husband, a primary school teacher who is on a sabbatical, and her younger son is at Wellington College.
Her last job was with the British Ministry of Education. She was responsible for the operational and capital funding of schools and for overseeing the major change of turning secondary schools into academies, or to "free schools" - similar to charter schools in that they are free of charge, state-funded schools, but independently run under contract with the state.
"I really loved the work but just wanted to get out of the big city and I just heard about this job and thought this would be a great place to go next."
She believes there have been advantages in coming from the outside.
"I think you do bring a completely fresh perspective. You see things more clearly for a little while, but you don't understand the nuances and complexities as well. It takes you a while to understand those."
Asked if she had experienced any prejudice she says "in recent days there have been one or two references to my English background. It's not a serious impediment to anything I need to do."
She is chirpy, relaxed, and says she has the best job in the world in one of the nicest places in the world.
Ms Longstone's interview panel comprised State Services Commissioner Iain Rennie, professional director Paula Rebstock, former Ministry of Social Development chief executive Peter Hughes and Wellington College principal Roger Moses.
It has been suggested, not fancifully, that Ms Longstone was appointed because she is an outsider, not despite it.
The education sector, long a difficult one to manage for National governments, was particularly toxic after the implementation of the national standards policy, which was resisted by many teachers and was against the judgment of many in the ministry.
Ms Longstone's predecessor, Karen Sewell, earned respect within National for doing what should be a relatively basic job of the public service - implementing government policy. But that goes to show how the ministry is historically seen by National governments as being bound closely with the teacher unions and Labour.
The next big step in National's agenda was the now ill-fated increase in class sizes, ostensibly to fund professional development of teachers.
With the combination of a new Secretary of Education, a new Minister of Education in Hekia Parata, and negligence among experienced ministers, the deep flaws of the formula were not tested beforehand. The policy was cancelled at great embarrassment to the Government.
Another of the big controversies has been the restructuring plans of schools in post-quake Christchurch.
Ms Longstone says that in hindsight there are things she would do differently to handle it better but she does not believe closing schools can ever be a pain-free process.
"I don't think there is a way to make people happy about the way you do that."
One of the biggest challenges in the immediate future is to address the Government's Better Public Service Results goals.
Three out of 10 are to be overseen by her, including increasing the number of 18-year-olds having NCEA level two to 85 per cent by 2017.
The 2011 rate for all school leavers was 78.5 per cent. But it was 60.9 per cent for Maori school leavers and 71.8 per cent for Pacific students.
"That is driving a lot of our work at the minute ... and we know we won't reach any of those targets unless we address the issues of Maori Pacific learners."
The disparity is evident in other measures - New Zealand is seventh out of 65 countries in the latest OECD Pisa assessment for 15-year-olds. But broken down, New Zealand Europeans are second, Maori are 34th and Pacific students 44th.
Some people attributed the disparity in achievement to poverty, she said.
"I don't agree with that analysis. I do agree that poverty makes a difference, but what I don't agree with is that that explains everything because all those OECD countries have poverty."
There was already plenty of evidence about what affected education, and poverty was only one factor.
"It is about really understanding the child in their context, understanding where they are coming from, having strong ties between schools and families and whanau, and just the quality of the teaching and learning practice that happens within the classroom."
There was excellence in the system already.
"I don't blame teachers for where we are, but it is a truth that we can't do without teachers because, fundamentally, achievement is based on what goes on between the learner and the teacher."
It was a matter of working out what each part - the ministry, teachers, school leaders, the community - could do better.
"So I don't feel beleaguered. We've got lots of real challenging things to do. But they are all important things and they are good things to do.
"I'm just getting on with the job."