That is what he claimed. However, his design document instructs the AI to download the codebase, references specific files in the codebase, and to create a rewrite of the same project by name. It seems very unlikely it didn't look at the code while working, even forgetting that it had already likely been trained on it.

He would have had a better argument if he created a matching spec from scratch using randomized names.

Conveniently ignoring the likelihood that Claude had been trained on the freely accessible source code.

Does he have access to Claude's training data? How can he claim Claude wasn't trained on the original code?