Edit: Also, the CEO sold stock not even two weeks in advance https://www.bloomberg.com/news/articles/2023-03-10/svb-chief...
These things can come at you fast. They probably put in the trade instructions sometime last year and they are not permitted to make modifications to the 10b5-1 when they do come into material non-public information as that is itself insider trading.
Trading (or changing a 10b5-1 plan) while in possession of material non-public information, whether in your favor or not, is insider trading.
Canceling a 10b5-1 is not in and of itself a violation, correct, but it can kill your affirmative defense as it jeopardizes the good faith element.
However, they would have had to have entered into the 10b5-1 prior to them coming into material nonpublic information in the first place for it to have been valid at all. My point is they made the decision to sell before they knew what was happening and filed a compliant trading plan.
Sounds fair, but lucky.