It's confusing to think of TDD as its own rationality technique: testing your belief that a piece of code works is not fundamentally different from testing any other belief.

No rationality technique is "fundamentally different" from fixing of any other kind of incorrect beliefs. You've just made an absolutely general counterargument.

(With TDD, you also test that the code didn't work before the bugfix (in the specific way), and started working as a result of it. It's too easy to fix nonexistent problems.)