This is why the Internet is such a bad source for news. A guy at a shop says something's true, you can find something somewhere online to confirm it, therefore it's true?
What you're missing is a huge amount of additional information. First, at the time this story broke there was no "the owner" of Advanced Nutrients. There was three co-founders that collectively owned the company. The guy (Gino Yordanov) accused of this crime (and, for the record, there's reason to suspect a political motive behind that accusation) was one of them.
Since this happened (more than a year ago) Michael Straumietis (sp?) bought out the other two owners. I've heard various speculation as to why he did that, ranging from him wanting more complete control over the company's direction to a desire to distance the company from the above scandal. My guess is it's probably a combination of more than just one thing.
Of course the guys screaming for a boycott and looking for blood don't want to stay current because if they stop listening for new information they don't have to worry about it contradicting what they've already decided must be true and therefore justifies their righteous fury. If this guy and his suppliers all want to boycott the company based on something someone no longer affiliated with it might have done... well that's their right.
For whatever reason, AN got rid of Gino. Maybe he wasn't a good guy, or maybe he was and he sold his share of the company because he knew that no matter how innocent he might be, the stink of this scandal would follow him and the company around forever. Maybe he decided he wanted the company he helped build to have the best chance at success even if his life would never recover from the accusation. I don't know.
But, most importantly, I'm not trying to stir up a lynch mob based on things I don't know but have decided are true.