That may explain the aghast reaction from her office, which first said her comments were being misinterpreted, then resorted to the plaintive cry that she had been "ambushed".
Really, her advisers are unhappy because she has been caught out - caught out telling the truth.
She has revealed the Cabinet's firm conviction that freemarket ideology is as applicable to purchasing school education as it is to buying a BMW or a nice dinner at one of Simon Gault's restaurants.
At first blush, her proposal has an attractive simplicity. Why shouldn't we give more funding to schools that provide a better education, just as we would pay more to any producer, manufacturer or service provider who offers us a better product?
Here's the difference, though: Our children are not customers purchasing an education commodity from their schools. Our children are the commodity. They are the raw material we feed into the schooling system at age 5. They are hewn into shape by their teachers and come out the other end as the finest young men and women their teachers can make them.
Schools must do their best with the raw material we give them. Some schools get to work with healthy, well-nourished children from well-educated families; other schools must work with the children of the poor, of immi- grants who don't speak English, and children with special needs.
Teachers at those schools will do their best. Sometimes they will perform miracles. But they will struggle to get their pupils to the same levels as the schools in the leafy suburbs.
Hekia Parata, it seems, would have us reward those schools whose pupils progress further and faster. Presumably, she believes this would provide struggling, straggling schools with the cash incentive they need to catch up.
If so, she is wrong. In the US, George W. Bush tried much the same thing with No Child Left Behind, tying funding to year-on-year improvement in standardised tests. The policy served only to increase the gap between the top schools and the bottom ones, penalising children at the latter.
Yes, minister, decile funding is a blunt instrument.
But it is better we sharpen the instrument than drop needs-based funding entirely.