A strict tests-must-be-written-ahead-of-time TDD advocate might say that writing the tests last is an error like p-hacking (choosing the threshold of statistical significance after the experiment) is an error.

Having always suspected that test-first TDD was most correct like adhering to the Scientific Method is most correct, I suspect that there are unmeasured differences between the results. But perhaps test-first TDD is a sham in AI and IRL