You appear to want to die on the hill of "This vulnerability would never have been found if we lived in a world without LLM AI" which is a very strange hill to die on.

There's no question that we live in the world where LLM AI was involved in finding the copy fail vulnerability at this specific time, and it's completely normal for people to see a vulnerability and then look closer and find related vulnerabilities or a deeper root cause, but there's no need to adopt an extreme "without AI LLM we don't find these vulnerabilities" position.

It seems as though this issue occurred to him, then he used their tool ("Xint Code") to analyze the codebase for instances of it.