No one (as far as I know) was aware of his selling out. And he sold way before the whole bankruptcy fiasco, for his own reasons, not because he gave up hope for the technology. I think the share price was around a dime when he sold.
He was going through a financial crisis involving his own company, that had nothing at all to do with Medizone.
I only found out about this after Marshall filed for bankruptcy, and I called this investor asking what the heck is going on. That's when he told me that he was no longer involved with Ed, and had sold off months before.