My speculation would be that Pestell simply


wasn't prepared to work within the confines of a micro-cap pharma on the razor's edge with respect to funding and this caused escalating difficulties between him and Nader.

My guess is that Richard felt like his work came at a premium, which Nader couldn't reconcile with the bottom line, so Pestell tried to act to make that financially happen, which Nader felt was a threat to the company's leverage in future deals. Probably boils down to who was more realistic.