diff --git a/scripts/dc-node-carve.sh b/scripts/dc-node-carve.sh
index 0f65f19..e6a4246 100755
--- a/scripts/dc-node-carve.sh
+++ b/scripts/dc-node-carve.sh
@@ -264,10 +264,15 @@
   if [ "$got" = "static:$ip" ]; then ok "$nic -> STATIC $ip on $cidr (read back '$got')"; MUTATED=$((MUTATED+1)); return 0
   else bad "$nic: link read back as '$got', wanted 'static:$ip'"; return 1; fi
 }
-# do_unlink <sysid> <ifid> <linkid> <nic>
+# do_unlink <sysid> <ifid> <linkid> <nic> <reason>
+# The REASON is a parameter, not a constant: this is called for two different
+# reasons (moving a member's L3 onto br-ex, and converting a commissioning auto
+# link to STATIC) and a hardcoded one made the plan for the metal-admin leg read
+# "L3 moves to br-ex", which is false. A mutation log that states the wrong
+# reason is the confident-but-wrong evidence class this repo keeps paying for.
 do_unlink(){
-  local sid="$1" ifid="$2" lid="$3" nic="$4"
-  if [ "$COMMIT" != 1 ]; then echo "  [plan] unlink $nic(id=$ifid) link id=$lid (L3 moves to br-ex)"; return 0; fi
+  local sid="$1" ifid="$2" lid="$3" nic="$4" why="${5:-}"
+  if [ "$COMMIT" != 1 ]; then echo "  [plan] unlink $nic(id=$ifid) link id=$lid ($why)"; return 0; fi
   m interface unlink-subnet "$sid" "$ifid" id="$lid" >/dev/null 2>&1 || { bad "$nic: unlink link id=$lid failed"; return 1; }
   reload_ifaces "$sid"; ok "$nic: unlinked id=$lid (now $(if_l3_count "$nic") L3 link(s))"; MUTATED=$((MUTATED+1))
 }
@@ -295,7 +300,7 @@
       lid="$(if_link_id "$nic" "$cidr")"
       if [ -n "$lid" ]; then
         note "$nic holds a commissioning '${link%%:*}' link on $cidr -- converting to STATIC $ip"
-        do_unlink "$sid" "$ifid" "$lid" "$nic" || return 1
+        do_unlink "$sid" "$ifid" "$lid" "$nic" "converting the commissioning ${link%%:*} link to STATIC" || return 1
         ifid="$(if_field "$nic" id)"
       fi
       ;;
@@ -338,7 +343,7 @@
         for l in (i.get("links") or []):
             if l.get("subnet"): print(l.get("id"))
 ' "$nic" 2>/dev/null); do
-    do_unlink "$sid" "$ifid" "$lid" "$nic" || return 1
+    do_unlink "$sid" "$ifid" "$lid" "$nic" "L3 moves to br-ex" || return 1
   done
 
   # 2) create the OVS bridge, moving the parent onto the provider VLAN FIRST.