It is unclear why one of Apple's main patent people is leaving the company at such an opportune moment. Apple is currently engaged in patent lawsuits with a lot of high-rolling names - Samsung and HTC being the most recent that it filed complaints with the ITC about.
Moreover, the $4.5 billion bid for Nortel's patents that got won by the funny consortium named Rockstar Bidco, which includes Apple, got approved yesterday by US and Canadian courts, despite antitrust doubts, so Cupertino's patent holdings are now even stronger.
Well, the guy might have just felt overworked with all that litigation and patent mudslinging going on in the mobile industry right now. We kid, but it's certainly an interesting development that shows the patent lawsuit game might be far from over yet.