A good 10b5-1 should allow trades to be executed on your behalf even while you might hold non-public information. Useful for cash flow, so you can buy nice things.
But if you control the date of the announcement to line up with instructions in your 10b5-1 plan, that would probably look more like insider trading despite the plan.
Which is how legal insider trading for management works these days. Because cancelling a 10b5-1 is perfectly legal at any time.
So you could totally abuse the system by submitting 5 of them, designed to allow for different strategies, then cancelling some of them to pick specific trading strategies based on more recent insider info.
And this works: cancelling them is normal, so that won't even attract much attention. It's a matter of executing well on this loophole.
The exact dates are not necessarily set in advance in a Rule 10b5-1 plan. The broker can make the decision based on metrics specified in the plan.
I'm guessing that the sharp stock price rise caused by the announcement triggered the sale based on these predetermined metrics, as it was meant to be.
That is to say, this is a non story and the article only tries to whip up controversy where there is none.
You're right. Anyway, even if it was completely discretionary selling after the announcement wouldn't be insider trading (unless he knows something bad which hasn't been disclosed yet that will make the price go down later). But the intention to sell, however is triggered, gives an incentive to put a positive spin on the announcement and profit from it (hardly unique to this case, the price of the stock didn't move that much anyway).
It is part of the CEO's job to put positive spins on things and to boost the stock price.
All CEOs are given stock-based compensation and incentives, and virtually all of them setup these sale plans in order to be able to sell legally and above board.
If you, as a CEO looking ot maximise personal profit, know a sale order data is coming up then you postpone or bring forwards the announcement to maximise the potential for that sale.
But if you control the date of the announcement to line up with instructions in your 10b5-1 plan, that would probably look more like insider trading despite the plan.