diff --git a/lib/daemon/__tests__/gate-owner-notify-trace.test.ts b/lib/daemon/__tests__/gate-owner-notify-trace.test.ts
new file mode 100644
index 000000000..89619ca5c
--- /dev/null
+++ b/lib/daemon/__tests__/gate-owner-notify-trace.test.ts
@@ -0,0 +1,68 @@
+/**
+ * Pins today's owner derivation and notify-bridge filtering for a
+ * worker-opened gate (RT-162 finding 4: refuted).
+ */
+import { describe, expect, test } from "bun:test";
+import { deriveOwner } from "../handlers/gate.ts";
+import { parseEventBridgeRules, startNotifyBridge } from "../../notify-bridge.ts";
+import type { NotificationEvent } from "../../state/notifier-store.ts";
+
+function fakeBus(): {
+  onBroadcast(fn: (type: string, data: unknown) => void): () => void;
+  emit(type: string, data: unknown): Promise<void>;
+} {
+  const subs = new Set<(type: string, data: unknown) => void>();
+  return {
+    onBroadcast(fn) {
+      subs.add(fn);
+      return () => { subs.delete(fn); };
+    },
+    async emit(type, data) {
+      for (const fn of [...subs]) fn(type, data);
+      await new Promise((r) => setTimeout(r, 0));
+      await new Promise((r) => setTimeout(r, 0));
+    },
+  };
+}
+
+describe("RT-162 finding 4 mechanism", () => {
+  test("a hook-shaped gate:open on a herd subject derives owner human today", () => {
+    // The hook's message spells `rt gate open --subject herd:.../job` with
+    // no origin, so deriveOwner sees no runId and falls back to human.
+    expect(deriveOwner(undefined, () => null)).toBe("human");
+    expect(deriveOwner({ presentation: "wait" }, () => "herd:h1")).toBe("human");
+  });
+
+  test("an owner:human bridge rule delivers a human-owned gate and skips a herd-owned one, blind to subject", async () => {
+    const rules = parseEventBridgeRules(
+      [{ pattern: "gate/opened/*", category: "gate", title: "t", message: "m", owner: "human" }],
+      () => {},
+    );
+    const bus = fakeBus();
+    const delivered: NotificationEvent[] = [];
+
+    startNotifyBridge({
+      onBroadcast: bus.onBroadcast,
+      rules: () => rules,
+      enqueue: (e) => { delivered.push(e); },
+      paneFocused: async () => false,
+    });
+
+    // A worker's hook-followed gate:open on its herd subject: derived owner
+    // "human" (per the test above), subject is the herd job's own subject.
+    await bus.emit("event", {
+      id: "1",
+      topic: "gate/opened/g1",
+      payload: { owner: "human", subject: "herd:h1/job" },
+      emittedAt: 1,
+    });
+    await bus.emit("event", {
+      id: "2",
+      topic: "gate/opened/g2",
+      payload: { owner: "herd:h1", subject: "herd:h1/job" },
+      emittedAt: 2,
+    });
+
+    expect(delivered.map((e) => e.id)).toEqual(["1"]);
+  });
+});