A 2026 study found humans are quietly being gentler on AI-authored PRs than on human-authored ones. Single-reviewer review already broke at 400 lines per diff. The fix is two old ideas — distribute the review across the team, and pair every diff with a deterministic map of the code flow.

Apple's "do not hallucinate" prompt is funny. The same logic is why AI-written + AI-reviewed pipelines silently approve bugs, why long contexts compound errors, and why the real guardrails are deterministic.