OPINION: Fonterra chairman John Wilson says Theo Spierings' decision to quit as chief executive had nothing to with the fact the company had just posted a $348 million loss.

That may well be true. New Zealand's largest company does not react to "one-off things".

Whether or not the co-operative's troubled investment in China's Beingmate should have prompted the chief executive to go, Fonterra has proved itself to be above reacting to its troubles.

Time after time, the co-operative's missteps have made its top management and board of directors appear tone deaf and flat-footed. Why should it react now?

READ MORE: Fonterra and Beingmate - where did it all go sour?

The troubles with Beingmate are major, especially after it emerged that it chose to invest over becoming a cornerstone shareholder in A2, the wildly successful producer.

And it is not the first time the company has been in trouble in China.

While the Sanlu melamine milk tainting scandal preceded Spierings, there were repeated troubles under his watch.

Fonterra and MPI sat quietly on news that trace levels of nitrogen inhibitor DCD had been discovered in milk. When in early 2013 the news was inconspicuously announced, in a way it was hoped would keep the issue quiet, Fonterra blamed the media when it created a storm.

If farmers hoped lessons may have been taken from DCD, only months later the company was dealing with a much larger problem.

Late on a Friday night, Fonterra revealed that a product used as an ingredient in infant formula might contain a bacteria that caused botulism, a potentially fatal form of food poisoning.

In the days following that news, Fonterra seemed have a surprising amount of trouble tracking down the product.

Although it ultimately proved to be a false alarm, the Prime Minister had to personally travel to China to give one of the world's least transparent countries reassurances about New Zealand's food safety standards.

During the visit, Wilson flatly denied he was even embarrassed by the trip.

But if Spierings wasn't going to lose his job over that kind of diplomatic humiliation, why should a bad investment decision make a difference?

Although the company would be fined by the Wellington District Court over food safety breaches, and later ordered to pay $183 million in recall costs to Danone, Fonterra insisted it had always acted in the best interests of consumers and the co-operative.

Fonterra's chairman and chief executive sailed above other troubles. When times were tough in early 2016, as global prices sank, the company used a time-honoured trick to improve cash flow: delay paying your bills.

Companies were told they would have to wait up to 90 days to get what they were owed.

Thousands of suppliers across the country were affected. A decision made by the corporate office ended up pitting farmers against small business owners across the country.

National Party MPs were publicly accusing the company of not caring about suppliers and discussing "inviting" management to front the party caucus.

Surely this should have been a hint that the company was off-side with its base.

There were bonus payments while farmers were losing money.

As water quality became an issue of national debate, Fonterra allowed the battle to go on around it.

In August, a group of leading figures signed the Farming Leaders' Pledge, setting a worthy (if slightly vague) goal of making New Zealand rivers swimmable.

While Fonterra chairman John Wilson signed up to the pledge, he was apparently too busy to attend the launch. That no one attended the launch in his place was striking.

Fonterra has never appeared more nimble than when it announced Spierings' departure, midway through a press conference at which it was expected that he and Wilson would face calls to quit anyway.

Wilson faces a re-election vote at this year's AGM, which could shape up as a test of his legacy.

Unless, of course, he elects to stand down, for reasons which will have nothing to do with all the one-off problems.