diff --git a/src/agent_comms/tools.py b/src/agent_comms/tools.py
index f07fe9a1eb..9400763226 100644
--- a/src/agent_comms/tools.py
+++ b/src/agent_comms/tools.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import json
+import threading
 from abc import abstractmethod
 from collections.abc import Mapping
 from pathlib import Path
@@ -1083,7 +1084,9 @@ def apply(self, comms: Comms, caller: ToolCaller) -> MessagePublished:
             body = VerdictAudience(self.audience).addressed(self.target, self.body)
             result = comms.messaging.send(self.sender, self.target, body, self.type, report=self.report)
         except ToolRefusedError as error:
-            SendRefusal.record(comms.root, self.sender, self.target, error)
+            # The caller hears the refusal now; the record waits for the wire lock on its own.
+            threading.Thread(target=SendRefusal.record,
+                             args=(comms.root, self.sender, self.target, error)).start()
             raise
         caller.sent(comms, result.message)
         return MessagePublished.from_send(result)
diff --git a/tools/upgrade_bus.py b/tools/upgrade_bus.py
index 8bb34727e6..ab7e53b27c 100644
--- a/tools/upgrade_bus.py
+++ b/tools/upgrade_bus.py
@@ -230,15 +230,19 @@ def carry_all(
 
 
 def copy_bus(root: Path, copy: Path) -> None:
-    """Copy under the bus's wire lock so no writer tears the copy; sockets are skipped."""
-    def sockets(directory: str, names: list[str]) -> set[str]:
+    """Copy under the bus's wire lock so no writer tears the copy; sockets and maintenance files are skipped."""
+    # The maintenance files describe the live root; a copy is a new root and starts open.
+    held = set(MaintenanceBarrier(root / "registry.json").witness_paths)
+
+    def skipped(directory: str, names: list[str]) -> set[str]:
         return {name for name in names
-                if stat.S_ISSOCK(os.lstat(os.path.join(directory, name)).st_mode)}
+                if Path(directory, name) in held
+                or stat.S_ISSOCK(os.lstat(os.path.join(directory, name)).st_mode)}
 
     from agent_comms.store_files import _store_lock
 
     with _store_lock(root / "wire"):
-        shutil.copytree(root, copy, symlinks=True, ignore=sockets)
+        shutil.copytree(root, copy, symlinks=True, ignore=skipped)
 
 
 def rehearsal_home(scratch: Path, root: Path, copy: Path) -> Path: