I offer an alternative view. The company is/was at the time well on its way, I think Jacobson just didn't fit in to the Cyanotech environment.
How do you know that Jacobson wasn't speaking to another co. about a job? That Cyanotech found out, and said leave now, not uncommon. And Jacobson is STILL on the board! This is truly interesting, but I think no reflection of the companies prospects.