| "It's a small change, a full review is overkill" | Supply-chain attacks, auth bypasses, and data leaks routinely ship as one-line diffs. Severity is decided by the attacker, not by the line count. Every diff crossing a trust boundary deserves the full attack-surface pass. |
| "The author is senior, I can rubber-stamp this" | Senior engineers write the most dangerous bugs because their code gets the least scrutiny. Reviewer accountability is independent of author rank — your sign-off is your signature, not theirs. |
| "CI will catch any real problems" | CI catches what its rules were written to catch: known lint patterns, test failures, maybe SAST signatures. It does not catch logic errors, authorization bypasses, race conditions, or novel attack vectors. Reviewers are the layer CI cannot replace. |
| "The tests pass, so the code is correct" | Tests prove the code does what the tests say — not what the spec says, and not what an attacker might induce. Adversarial review exists precisely because test coverage and attack surface are different sets. |
| "I don't understand this part, but it looks fine" | "Looks fine" in unfamiliar code is not a review — it is abdication. Either learn the area well enough to have an opinion, or explicitly flag the section as unreviewed and request a subject-matter expert. Silent approval is worse than no approval. |
| "Rubber-stamping saves team velocity" | Velocity gained by skipped reviews is paid back 10x in incident response, security patches, and postmortems. Every untriaged vulnerability in main is a scheduled outage whose date has not been set yet. |
| "This was already reviewed in a previous PR" | Previous reviews covered previous code. Rebases, refactors, and context changes can turn yesterday's safe code into today's vulnerability. Re-review the current diff against the current codebase — history is not exoneration. |