(I don't really think execs should be compensated with stock, but since they are you know they're going to be selling it regularly. Should they be prosecuted every time the price drops? Of course not, in fact they are almost never prosecuted.)
To enforce insider trading laws in a "fair" way would require a massive expansion of the SEC and related agencies, which expansion would be funded by the general fisc for the specific benefit of investors. There are arguments to be made for that, but they seem similar to the arguments one hears for more aggressive enforcement of our drug prohibition. Those who argue loudest are interested parties. I'd prefer we reverse our many-decades trend, and experiment with less enforcement rather than more. I doubt we're capable of that, but sometimes I indulge in optimism.
That's life.
EDIT: Interesting that this is downvoted, are you taking it as an indication that I'm attempting to say he got what he deserved with the above? That is not my intention, I'm simply pointing out that when you fight a bully, you often get a broken nose.