There is a 0% chance you could prove he sold for that reason. Also if you didn't notice the stock is only a few %pts from its ATH; and almost trading at the exact price he sold it at.
Intel and AMD were informed of the vulnerability in June. The stock is up significantly since then, if the CEO was selling for that reason you'd assume it would be much sooner after. In all likelihood this is for tax purposes. The SEC would likely never be able to prove otherwise. I also doubt the SEC even looks at it. There was heavy options volume leading into it though, which they might.
The timeline of events is ... interesting: Intel filed its quarterly report October 26 and the trades were initiated on October 30 and executed November 30. There's no doubt he knew. The big question is what lies ahead. When the patches hit, when people other than, how to say, geeks realize what's up then comes the question: does Intel stock drop? If it does, then even the company might come under fire for not disclosing a significant risk.
Not sure how this hurts Intel much, they essentially have a monopoly on the CPU space, AMD is only really competing because of their GPU unit. AMD can't scale to meet demand if there were a big shift from cloud providers. Even there Nvidia is miles ahead of everyone (GPU.) The thing is that, if anything, this could help Intel sales, because the only way to -truly- stop this is to get new chips...which Intel will provide, and vendors will have no choice for many larger clients. ARM chips have the same exploits (both variants.) AMD can't scale its business for that kind of demand, and its chips are slower...so what are you going to do?
I doubt the CEO is exactly shaking in his boots or sold for that reason. I'd even be willing to bet Intel will provide a fix on the hardware and continue to use the same sockets so cloud providers can just change them out without further hardware changes.
Intel's stock will probably trade down to 40, fill the gap and continue its uptrend, largely because the market is very bullish on the chip space right now.