I stopped asking NotebookLM questions and started making it argue with itself

I do BA/QA on insurance software — 80-page requirement docs that quietly contradict themselves. I'm supposed to catch that before UAT does. I usually don't.

What helped wasn't better prompts. It was making the notebook take a side.

I upload the BRD, the old version, and the signed change requests as separate sources — not one merged file. Then I ask it to act as the dev who has to build this and list every place two sources say different things. Then I ask it to act as the client who signed off and defend those same passages.

The gap between those answers is my defect list. Last month it caught a premium-calculation rule that had been silently reversed between v2 and v4. Three weeks on that project, nobody noticed, me included.

Keep the files separate — merged, it smooths the contradictions over. And spot-check citations; it'll occasionally pin a rule to the wrong doc, and a confident wrong citation is worse than none.

Still useless at counting. Ask if all five business rules are covered and it'll happily say yes. That part I still do by hand, badly, in a spreadsheet.

Anyone found a framing that beats adversarial?