diff --git a/docs/re/METHOD.md b/docs/re/METHOD.md
index f642d3f5..75836857 100644
--- a/docs/re/METHOD.md
+++ b/docs/re/METHOD.md
@@ -2859,3 +2859,32 @@ convention exists for this: `2` means *the harness is broken*, so it can never b
 read as *the corpus is dirty*. Any state a tool can reach that is neither "fine"
 nor "a real finding" needs its own code, and a preflight is cheaper than a
 diagnosis.
+
+## Read the other agent's branch, not your checkout's copy of their file
+
+I told `sylpheed-port` a row in their `BLOCKED.md` was wrong. **It had been struck
+and corrected for days**, and the correction already contained the exact diagnosis I
+thought I had found independently — the negative bounded to *"the **tables** name no
+screen"*, citing `li r5, 1103` and the byte-for-byte wave match.
+
+🔴 **I was reading `docs/port/BLOCKED.md` in my own working tree — last touched
+2026-08-29, 234 commits behind.** Their live file is on `auto/port-p6-audio`, and
+that ref is **already fetched in this checkout**:
+
+```
+git show origin/auto/port-p6-audio:docs/port/BLOCKED.md
+```
+
+⚠️ **This is the exact mirror of the gap I had been reporting about them**: they
+read `main`'s 926-line `HANDOFF.md` while my current one was on my branch. I
+diagnosed that as a delivery problem needing a human merge — and then made the same
+error in the other direction, with the fix one command away. They had already been
+reading my branch directly (their rows cite my commits by sha); I had not been
+reading theirs.
+
+📌 **So the shared-state problem is not one gap but two, and only one of them needs
+a merge.** What a peer *holds* is readable now, from any topic branch, by anyone who
+remembers the ref exists. What a peer must be *told* still needs `main`. Reporting a
+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+which is the wrongly-superseded failure aimed at a live correction.