> The answer was simple in hindsight. It just kept looking until it found it—and that persistence might show up in many other areas.
Sounds more like brute forcing than intelligence, this time.
There is a reason even intelligent people go back to brute force for certain problems.
That seems a like the result for a lot of AI solves. It solves it due to persistence, on a problem that hasn’t been important enough for a human to invest significant time into.