A whistleblower is the type of person to refuse such an NDA, regardless of buy-off price. They would understand that if Boeing is willing to pay them 10 million or whatever, that the information they have, should they release it, prevent over 10 million dollars worth of damages to the public.
I just don't see someone like that committing suicide in a hotel parking lot out of state the day (two days?) before they are supposed to testify. That would go against everything they were doing up until that point.
There have been studies on motivation that have similarities to your descriptions. Basically, like you said, if we get a partial reward for a goal, we're less likely to accomplish that goal.
The one I remember had 'telling someone else your goal' as the 'partial reward'. At the end of a day, people who told someone their goal felt closer to accomplishing it, but less motivated to actually work on it. People who didn't tell anyone worked on their goal longer, but also felt like 'they still had a long way to go'.
I think the other part of it was what you said about not wanting to actually do X but prove to yourself that you COULD do X. Once I prove that I COULD.. I'm done. The goal might not be what other people would consider 'done', but my ADHD brain doesn't care. It got dopamine, and now we're moving on to the next topic.
What? The guy who fired people who slept in their offices at Twitter fired more people who were sacrificing their personal lives for one of his companies?