It has the same failure mode as dealing with TDD by a human engineer, which includes things like mocking the function under test in the test and then testing the mock, asserting only things that aren't actually exercised by the function under test (like asserting the initial user ID is the same as the final user ID for a function that changes name of a group), not validating side effect behavior (or lack thereof) for a function that's only purpose is the side effect (like appending a log line to a log file), and more!
What changes with TDD is that the important part of the review moves from the mainline code to all the TDD tests and the coverage, and you also need to see a test run from before the code changes with all the new/updated TDD tests failing in addition to just a test run after the changes with all the (at least) new/updated TDD tests passing.
What changes with TDD is that the important part of the review moves from the mainline code to all the TDD tests and the coverage, and you also need to see a test run from before the code changes with all the new/updated TDD tests failing in addition to just a test run after the changes with all the (at least) new/updated TDD tests passing.