It may not have been very diplomatic. And his boss probably won't thank him for it. But Maurice Williamson has done the country a huge favour in exposing the real story surrounding the Crafar farms and Chinese pressure on New Zealand.
He has done so by releasing a letter to him from Murray McCully in which the Foreign Minister issues a blunt warning about the impact on trade and economic relations with China if the application by Chinese interests to buy the Crafar farms had been declined.
Accompanying documentation shows a high level of concern within the Government about the impact on potential investors - and not just Chinese ones - of February's High Court ruling overturning Williamson's and Jonathan Coleman's ministerial approval of the sale.
The material also shows that the Crafar case was being closely watched by Chinese authorities. It was raised in talks with Trade Minister Tim Groser. New Zealand officials developed a special strategy to clear up the "confusion" surrounding the court's decision.
As late as Monday the Prime Minister was steadfastly denying any pressure "at all" had come from the Chinese. The material released by Williamson would suggest the opposite. Pressure comes in very different forms. An elephant does not have to apply much of it to squash a mouse.
As one of the two ministers who have now twice okayed the sale, Williamson will be forever accused of selling out on his country. He can live with that. What has clearly frustrated him is the shallow nature of the debate on foreign investment and the feeling that New Zealanders want to have their cake and eat it too.
In releasing McCully's letter, Williamson has exposed a few home truths about the consequences of that kind of behaviour.
The question now is whether - as Peter Dunne, another voice of reason, said yesterday - there can now be a proper debate on what levels of foreign investment New Zealanders really want.
Few other issues are crying out for some kind of cross-party parliamentary consensus. Or will the country just twiddle its thumbs and wait for the next Crafar and the same kind of unthinking Pavlov's dogs-type reaction from most quarters.