diff --git a/bin/fm-teardown.sh b/bin/fm-teardown.sh
index b49831776e2..81c66c08afa 100755
--- a/bin/fm-teardown.sh
+++ b/bin/fm-teardown.sh
@@ -83,10 +83,11 @@
 # name a slot a DIFFERENT live task now holds. Cleanup kills every process under
 # that path and hard-resets it before returning it, so releasing a slot that is
 # not genuinely this task's destroys another worker's live work. Before the first
-# cleanup step, teardown verifies record exclusivity: no OTHER task record in
-# this home or any locally registered Firstmate home may name the same live path
-# in its worktree= or home=. One live path with two task records is the reuse
-# collision itself, whichever record is stale.
+# cleanup step, teardown reads the slot claim. If this task still owns the slot
+# (or the claim is absent), it verifies record exclusivity: no OTHER task record
+# in this home or any locally registered Firstmate home may name the same live
+# path in its worktree= or home=. Two records naming this task's slot refuse its
+# return; a positively reassigned slot is never returned.
 # That scan alone cannot prove THIS record is the current owner, because the task
 # that took the slot next may leave no record it can reach - its own worker may
 # have exited and its record been cleaned up, or it may live in a home this
@@ -2376,8 +2377,9 @@ require_exclusive_task_worktree_slot() {
 # Positive slot ownership, read from the claim the task that took the slot wrote
 # into the slot itself (bin/fm-wake-lib.sh owns the claim and its states).
 #
-# The record scan above proves that no OTHER task record names this slot. It
-# cannot prove that THIS record is not the stale one, because the task that took
+# The record scan, when this task still owns the slot, proves that no OTHER
+# task record names it. It cannot prove that THIS record is not the stale one,
+# because the task that took
 # the slot next may leave no record this scan can reach: its own worker may have
 # exited and its record been cleaned up, or it may belong to a home this machine
 # does not register. The claim closes that gap from the other side - it names the
@@ -2387,8 +2389,9 @@ require_exclusive_task_worktree_slot() {
 #
 # A claim naming another task does not refuse: it means the slot is no longer
 # this task's, so the record's own cleanup proceeds and every slot step is
-# skipped (see the script header for why refusing would strand the record and
-# why skipping discards nothing). Returns TEARDOWN_SLOT_REASSIGNED_RC for that
+# skipped, including the exclusivity scan that would reject the other task's
+# legitimate record (see the script header for why refusing would strand the
+# record and why skipping discards nothing). Returns TEARDOWN_SLOT_REASSIGNED_RC for that
 # state so each caller gates its slot steps on one determination; the claimant
 # stays in FM_TREEHOUSE_SLOT_OWNER_ID and FM_TREEHOUSE_SLOT_OWNER_HOME.
 #
@@ -3308,8 +3311,10 @@ remove_secondmate_registry_entry() {
   return "$rc"
 }
 
-require_exclusive_task_worktree_slot || exit 1
 require_owned_task_worktree_slot || exit 1
+if teardown_owns_worktree; then
+  require_exclusive_task_worktree_slot || exit 1
+fi
 
 validate_pr_poll_cleanup "$STATE" "$ID" || exit 1
 
diff --git a/docs/architecture.md b/docs/architecture.md
index 1180e6223c9..da8a2e1aee6 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -408,7 +408,8 @@ After the forge accepts firstmate's merge request, the merge path persists the r
 A later merged poll consumes only that matching persisted value; with no match it records the landing as external rather than consulting a live away-posture record that may have been archived or replaced.
 [`bin/fm-merge-authority-lib.sh`](../bin/fm-merge-authority-lib.sh)'s header owns resolution, private atomic persistence, identity-checked consumption, and retirement, while only the merge path gates on the answer.
 Teardown is fail-closed for ship worktrees: dirty worktrees refuse, and committed work must be landed before the worktree is returned.
-A pool worktree is only returned after teardown passes the slot-ownership proof: a contradictory task record or a supported live endpoint refuses without touching either task, and no discard authority relaxes that.
+A pool worktree is only returned after teardown passes the slot-ownership proof: when the slot claim names this task or is absent, a contradictory task record or a supported live endpoint refuses without touching either task, and no discard authority relaxes that.
+A claim naming another task proves reassignment, so teardown skips every slot operation and cleans up only the stale task record.
 A slot's own owner claim, written by the spawn that takes it under the allocation lock and owned by [`bin/fm-wake-lib.sh`](../bin/fm-wake-lib.sh), covers a slot reassigned to a task that left no record the scan could reach: a claim naming a different task releases nothing - teardown warns, names the claimant, and finishes only the task's own cleanup - because Treehouse's own live process lease cannot answer ownership once the worker's exit releases it.
 Allocation and return serialize on one project lock per machine-local Firstmate tree: every home reachable through local parent links shares that lock, and a home seeded from another machine anchors its own, because a lock taken on this filesystem is neither held nor observable across that boundary.
 Before the worktree is returned, teardown concludes the task's own no-mistakes run when it is parked at a gate, including a run whose head the task copy cannot resolve - the shared runs-ledger continuation proof is the only recognition for that case, so cleanup never orphans a parked run the pipeline advanced past the submitted head.
diff --git a/tests/fm-teardown-endpoint-safety.test.sh b/tests/fm-teardown-endpoint-safety.test.sh
index 01dc74239e6..ee9150c82bf 100755
--- a/tests/fm-teardown-endpoint-safety.test.sh
+++ b/tests/fm-teardown-endpoint-safety.test.sh
@@ -550,6 +550,80 @@ test_reused_pool_slot_refuses_before_touching_the_other_task() {
   pass "fm-teardown: a pool slot named by a second task record is never returned, killed, or reset"
 }
 
+# Two records can name one slot after reuse. Only the slot's positive claim
+# distinguishes the stale record from its current owner; an absent or unsafe
+# claim never licenses either record to release the contested slot.
+test_shared_slot_claim_distinguishes_stale_from_current_owner() {
+  local dir id=stale-task other=current-task scenario target rc
+  for scenario in stale current absent unsafe; do
+    dir=$(make_case "shared-slot-$scenario")
+    mark_case_as_treehouse_pool "$dir"
+    fm_write_meta "$dir/home/state/$id.meta" \
+      "window=firstmate:fm-$id" "endpoint_task_id=$id" \
+      "worktree=$dir/worktree" "project=$dir/project" "kind=scout"
+    fm_write_meta "$dir/home/state/$other.meta" \
+      "window=firstmate:fm-$other" "endpoint_task_id=$other" \
+      "worktree=$dir/worktree" "project=$dir/project" "kind=scout"
+    target=$id
+    case "$scenario" in
+      stale) claim_pool_slot "$dir" "$other" ;;
+      current) claim_pool_slot "$dir" "$other"; target=$other ;;
+      absent) ;;
+      unsafe) printf 'not-a-claim\n' > "$dir/pool/1/.fm-slot-owner" ;;
+    esac
+
+    set +e
+    run_case "$dir" "$target" > "$dir/stdout" 2> "$dir/stderr"
+    rc=$?
+    set -e
+    if [ "$scenario" = stale ]; then
+      [ "$rc" -eq 0 ] || fail "stale record could not finish its own cleanup: $(cat "$dir/stderr")"
+      assert_reassigned_slot_left_alone "$dir" "$id" "$other" "shared-slot stale record"
+      assert_present "$dir/home/state/$other.meta" "stale cleanup removed the current owner's record"
+      assert_present "$dir/worktree/sentinel" "stale cleanup changed the current owner's copy"
+      assert_contains "$(cat "$dir/runtime.log")" "fm-$id" \
+        "stale cleanup did not close its own endpoint"
+      ! grep -F "kill-window" "$dir/runtime.log" | grep -Fq "fm-$other" \
+        || fail "stale cleanup closed the current owner's endpoint: $(cat "$dir/runtime.log")"
+    else
+      [ "$rc" -ne 0 ] || fail "contested slot with $scenario claim was returned"
+      assert_present "$dir/home/state/$id.meta" "refusal erased the stale task record"
+      assert_present "$dir/home/state/$other.meta" "refusal erased the current task record"
+      assert_present "$dir/worktree/sentinel" "refusal changed the contested copy"
+      [ ! -s "$dir/runtime.log" ] \
+        || fail "contested slot with $scenario claim reached the runtime: $(cat "$dir/runtime.log")"
+      if [ "$scenario" = unsafe ]; then
+        assert_contains "$(cat "$dir/stderr")" "$dir/pool/1/.fm-slot-owner" \
+          "unsafe claim refusal did not identify its file"
+      else
+        assert_contains "$(cat "$dir/stderr")" "$other" \
+          "contested slot refusal did not name the other record"
+      fi
+    fi
+  done
+
+  # Ordinary cleanup of a completed ship must skip the current owner's dirty
+  # slot even without --force; the two task records still name the same copy.
+  dir=$(make_case shared-slot-completed-ships)
+  mark_case_as_treehouse_pool "$dir"
+  fm_write_meta "$dir/home/state/$id.meta" \
+    "window=firstmate:fm-$id" "endpoint_task_id=$id" \
+    "worktree=$dir/worktree" "project=$dir/project" "kind=ship"
+  fm_write_meta "$dir/home/state/$other.meta" \
+    "window=firstmate:fm-$other" "endpoint_task_id=$other" \
+    "worktree=$dir/worktree" "project=$dir/project" "kind=ship"
+  claim_pool_slot "$dir" "$other"
+  FM_HOME="$dir/home" FM_ROOT_OVERRIDE="$ROOT" \
+    FM_RUNTIME_LOG="$dir/runtime.log" PATH="$dir/fakebin:$PATH" \
+    "$TEARDOWN" "$id" > "$dir/stdout" 2> "$dir/stderr" \
+    || fail "completed ship's stale record could not clean up without --force: $(cat "$dir/stderr")"
+  assert_reassigned_slot_left_alone "$dir" "$id" "$other" "completed ship without --force"
+  assert_present "$dir/home/state/$other.meta" "completed ship cleanup removed the current task record"
+  assert_present "$dir/worktree/sentinel" "completed ship cleanup changed the current owner's dirty copy"
+
+  pass "fm-teardown: a positive other-task claim cleans only the stale record; current, absent and unsafe claims cannot release a contested slot"
+}
+
 test_cross_home_pool_slot_collision_refuses() {
   local dir id=stale-task other=secondmate-task second_home second_project rc
   dir=$(make_case slot-reuse-cross-home)
@@ -1400,6 +1474,7 @@ test_orca_close_failure_refuses_even_under_force
 test_already_gone_endpoint_still_completes_without_a_refusal
 test_bare_relative_origin_shares_project_lock_with_clone
 test_reused_pool_slot_refuses_before_touching_the_other_task
+test_shared_slot_claim_distinguishes_stale_from_current_owner
 test_cross_home_pool_slot_collision_refuses
 test_sole_slot_record_still_tears_down
 test_reassigned_pool_slot_finishes_own_cleanup_without_touching_the_slot