To be fair, the title is "I wrote a C++ ray tracer from scratch without AI", not "This C++ ray tracer, right now, contains no AI-written code"

It sounds to me like there is some point in this project's history when both of the following were true:

1) It was a C++ raytracer

2) It was entirely human-written

So technically there is no lie here.

Wow, I also wrote a game 8 years ago and have been using AI to rebuild upon it. I'm excited to tell people that I wrote it from scratch without AI! Love these new rules!