A resignation date is not necessarily a departure date, it's just the date the person gave notice. Again, think about what you are saying! In your interpretation, every time a CEO of any company tendered their resignation, the company would be in immediate non-compliance with the SEC. I seriously doubt that is the case. Further, I'm certain that SEC grants some grace period for companies that are blind-sided by an abrupt resignation and instant departure (like in a case where the CEO is pissed or under review for possible wrongful behavior and escorted out). Per the SEC filing you quote, Atul is leaving under agreeable terms; why wouldn't he include a few weeks notice?
Wait till Atul is known to be actually gone (and not using accrued vacation, if he so chose), then shoot your flares.
You make me want to use "the forbidden word"!
SGE