It's like a doctor deciding not to tell a patient they could be at risk. You don't get to defend the lack of consent by saying, "I think I made the right judgment."
The right thing to do is always - always - trust people, and make as much information available as possible. Even to the extent of being upfront about what you don't know. When that doesn't happen, people learn that governments can't be trusted.
The Centre for Disease Control in the United States has a manual on how best to communicate in health scares such as Ebola: "Describe the steps you are using to get the facts and help the audience deal with the uncertainty while all the facts are uncovered."
In other words, tell people what you know, what you don't know, and what you're doing to find out what you don't know.
The National Party spent most of the 2000s alleging the creation of a nanny state. How much more nanny state can you get? It is not possible to make a more anti-family decision than to know of a risk to an infant and refuse to tell the infant's parents. Removing the right of parents to make decisions about the safety of their own children is to insert the state directly as nanny and remove the ability of parents even to know they have been displaced as primary carer.
The state will always juggle conflicting interests; the health of babies versus the damage to dairy exports, or political risk versus safety.
Only parents have the interest of the child, solely and completely in the centre.
Consider the counter-factual: that the madman actually went through with poisoning. The Government, Federated Farmers and Fonterra knew this was plausible, because that's why they started a special testing programme. In that case an infant would have been poisoned and probably died. How could you have let me feed my child that formula when you knew of the risk it was poisoned?
That fortunately no one has been poisoned can't change the underlying morality. A shooter who misses is as morally culpable as a shooter who hits.
Powerful men believed they knew what was best for women and our children. Funny how they always do. The same logic has always been used, by doctors, politicians, men in power, to make decisions about women, and our children, and what's best for us.
They didn't want to create "panic", a cliched reference to women as emotionally unstable and unable to make rational choices. It's frankly bizarre we are allowed to vote when powerful men can make considered and temperate decisions on our behalf.
Had parents been given the choice, most would have reacted calmly - and imported overseas-made infant formula.
This would have damaged our infant formula exports in the short term. But we would have recovered.
Here's a message to these powerful men who are still living in the last century or the one before: we don't want you making those decisions.
We want the information you have been given so that we can make meaningful decisions for ourselves. Taking that right away is unforgivably arrogant.
Josie Pagani is a centre-left political commentator and former Labour Party candidate.