"So he [Spierings] has done the right thing by going directly to China to be the man on the ground," the source said. "Clearly there will be some heads, but that's for later."
New Zealand's reputation for high-quality food products - the driving force behind $2 billion in annual dairy exports to China - took a hit in January when traces of dicyandiamide, a nitrate inhibitor, were found in New Zealand milk.
Federated Farmers has so far kept its own counsel on the latest issue, choosing instead to let Fonterra and the Ministry for Primary Industries deal with the problem.
Privately, farmers are understood to be furious.
One central North Island farmer said the scare was likely to put downward pressure on the farmgate milk price, which has the greatest bearing on farm incomes.
"In the medium term it will do some damage to the brand because we command a premium for quality," he said. "If we can't provide that, then why pay for it?
"I would hate to be at the next Fonterra shareholders meeting - they will give them a bollocking,' he said. "The directors will be bracing themselves for it I think because they are so tough on farmers' milk quality."
One dairy analyst also stopped short of speculating that Spierings would go.
"It will be a test of his [Spierings'] credentials, that's for sure, so it will be interesting to see how he comes through," he said.
Spierings was appointed chief executive in 2011 - having previously headed the Dutch dairy giant, Royal FrieslandCampina - with big ambitions for Fonterra's role in China.