But Bai now says consumers have been distracted by the threat of tough new rules limiting how much imported milk powder they can take from Hong Kong back to the mainland.
"I think the pressure on New Zealand milk is easing somewhat in China after Hong Kong imposed a two-can rule that has diverted public attention," he says. "There is still a long way to go before the Chinese public confidence in domestic products can be restored, which may spell both opportunity and risks for New Zealand interests in China."
The risks being more of the same - scares and scandals.
Shanghai-based Kiwi dairy entrepreneur Howard Moore says DCD was a blip and nothing more, though its handling by officials left some things to be desired.
"They've forgotten about it already. It's gone," he says.
"It was a concern at that time but put it in the context of the melamine disaster, which was huge and which people are still talking about today. It [DCD] was a serious blip at the time, but believe me, it's gone."
New Zealander Nick Wheeler is a China veteran of 23 years and the general manager of International PR firm Ketchum's Beijing office.
Wheeler says key lessons from the DCD affair include the expectations that local consumers have for foreign products.
"This really does demonstrate that foreign products are held under even higher scrutiny than local products. There is a perception in China that international brands tend to be higher quality, safer, and that they adhere to higher food and safety standards," he says. "Anything that impacts on the quality of the product that they're giving to their one and only single child, generally speaking, is of course going to cause massive public concern.
"I think maybe one key takeaway for the New Zealand dairy industry is that the bar has just been set even higher for them because this whole DCD issue, which they probably didn't even think was a food safety issue. And perception is reality, right, so now they have to deal with it as a food safety issue even if they say it's not."
The Chinese are so sensitive to food scares both because they happen so often and because the reaction from companies in the wrong is often to flatly deny.
And when the Chinese public are used to being lied to by companies frantically trying to cover their backs it's no wonder they are so unforgiving at even the slightest whiff of a cover-up.
Let's clarify that: even the slightest whiff. That's all you need.
Executive director of the Public Affairs Asia network Craig Hoy advises perception and reality in these cases are one and the same, "which is why it is so important that companies get out in front of the story, even when they have bad news".
"When these issues flare up it is often because the company concerned has chosen to ignore the early warning signs.
"'No comment' is no longer an acceptable response. In China it is essential that companies try as far as possible to be seen to be in control.
"Any sign of a cover-up, or any hint of mixed messaging, and traditional and new media will be on to the story. In China, where bad news on issues such as food safety or public health has often been slow to break, the public is increasingly suspicious."
- Special correspondent