At one point in the dialog, Scott raises what I think is a valid objection to the "nine people in the basement" picture of FAI's development. He points out that it's not how science progresses, and so not how he expects this novel development to happen.

If we consider FAI as a mathematical problem that requires a substantial depth of understanding beyond what's already there to get right, any isolated effort becomes likely hopeless. Mathematical progress is a global effort. I can sorta expect a basement scenario if most of the required math happens to be already developed, and so the remaining challenge is to find the relevant math, assemble it in the right way, and see the answer. But that doesn't sound very likely.

Alternatively, a "team in the basement" could wait for the right breakthrough in the mainstream mathematics, and, being prepared, to apply it faster than anyone else to the problem. This seems more realistic, but may require the mainstream to know what to look for. Which involves playing with existential risk.