If that’s the scenario, I would be asking why the testing pipeline didn’t catch this rather than why was the AI SQL wrong.

Because the testing pipeline was generated by AI, and code-reviewed by AI, reading a PR description generated by AI.

Because the testing pipeline isn't the real database.

Anyone that knows a database well can bring it down with a innocent looking statement that no one else will blink at.

Sure, but everyone knows humans end up bringing down the database too by writing an innocent looking test query nobody else blinks at, which is why you end up needing a testing strategy for ANY SQL before YOLO'ing into prod.

To offer a 3rd option - what testing pipeline? Incompetent managers aren't going to approve of developers "wasting their time" on writing high quality tests.