I don't think that's what's being said. More like the complexities of the solution are taking a while to understand because it is a complex solution using complex math. Even the smartest people in their fields can't always look at a solution and at a glance understand everything without truly digesting what they're seeing.

It sounds more like when AI won in Go for the first time. People were looking at the game and saying "humans don't play like that, we don't understand those moves".

That is not at all what he just said

I think it's more that he's saying "interesting approach, but not verified yet."

Can you expand on how you came to this conclusion?