When Two AI Reviewers Agree: Building Assurance Quorums Without False Independence

TL;DR Adding a second or third AI reviewer can improve coverage, expose disagreements, and reduce some individual model errors. It does not automatically create independent assurance. Reviewers can share the same provider lineage, poisoned context, stale evidence, rubric, retrieval path, or false assumption and confidently reach the same wrong conclusion. Treat multi-model consensus as an advisory