method: a checker inherits the staleness of every file it scans

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v

docs/re/METHOD.md

@@ -2888,3 +2888,27 @@ remembers the ref exists. What a peer must be *told* still needs `main`. Reporti
 defect in a file you have not read at its head is worse than not reporting it:
 theirs was corrected, so my message asked them to re-fix something already fixed,
 which is the wrongly-superseded failure aimed at a live correction.
+
+## A checker inherits the staleness of every file it scans
+
+`check_refuted.py` scans all of `docs/`, which includes the files `sylpheed-port`
+authors. **Six of seven of my copies of those are days behind their branch head,
+and one I do not have at all.** So any verdict it reaches about one of their files
+is a verdict about *my copy*.
+
+Measured before acting: **zero** of today's hits land in a peer-owned file, so the
+exposure is **latent rather than active**. That is worth stating either way,
+because the failure direction is the false positive — flagging a claim the owner
+has already corrected — and I did exactly that by hand the same day, with their
+live file one `git show` away in a ref already fetched here.
+
+⚠️ **Reported, not excluded.** Silently skipping their files would hide the
+exposure, and being behind a peer's topic branch is the normal state — making it an
+error would be scenery within a day. The run now names which peer-owned files were
+judged from a stale copy, and prints the command to read the live one.
+
+📌 **The general form: a tool's reach includes the freshness of its inputs, not
+just their content.** A checker with a green light over a stale corpus is reporting
+on a snapshot, and nothing in its output says so unless it is made to. Ask of any
+scan not only *what did it look at* but *how old was what it looked at, and who
+owns it*.