The official story on Bertrand Serlet leaving Apple talks about Serlet's desire to focus less on products and more on science.
However, it would be interesting to visualize a scene where Serlet calls up Steve Job, while Job's is away on medical leave of absence. Imagine Serlet informing Job's that he intends to focus less on products and more on science. Job's is shocked, and feels angry at Serlet. Job's doesn't show it and reacts calmly in an even voice. He offers Serlet a raise, a generous triple percent point increase with the added sweetener of stock options. This is the best Job's can do. Job's knows what cooking inside Serlet. He made the offer, but he know that Serlet would not stay. This cold and short call would make make it final. The issue had been finally laid to rest.
Amazing! won't it be, if it turned out to be true.