diff --git a/src/main/runtime/rpc/methods/orchestration-send.test.ts b/src/main/runtime/rpc/methods/orchestration-send.test.ts
index d8a4212dbef..7b3ed47b38e 100644
--- a/src/main/runtime/rpc/methods/orchestration-send.test.ts
+++ b/src/main/runtime/rpc/methods/orchestration-send.test.ts
@@ -8,7 +8,9 @@ import type { OrcaRuntimeService } from '../../orca-runtime'
 import type { RuntimeTerminalSummary } from '../../../../shared/runtime-types'
 import { ORCHESTRATION_CONTRACT_VERSION } from '../../../../shared/protocol-version'
 
-function lifecycleGroupRecipientError(type: 'worker_done' | 'heartbeat'): string {
+function lifecycleGroupRecipientError(
+  type: 'worker_done' | 'heartbeat' | 'escalation' | 'decision_gate'
+): string {
   return `${type} messages belong to one exact Dispatch and cannot target a group address.`
 }
 
@@ -634,6 +636,27 @@ describe('orchestration RPC methods', () => {
       expect(db.getInbox(100)).toHaveLength(0)
     })
 
+    it.each(['escalation', 'decision_gate'] as const)(
+      'rejects %s group sends before inserting rows',
+      async (type) => {
+        setup()
+        const listTerminals = vi.spyOn(runtime, 'listTerminals')
+
+        await expect(
+          call('orchestration.send', {
+            from: 'term_worker',
+            to: '@all',
+            subject: `${type} broadcast`,
+            type,
+            payload: JSON.stringify({ taskId: 'task_1' })
+          })
+        ).rejects.toThrow(lifecycleGroupRecipientError(type))
+
+        expect(listTerminals).not.toHaveBeenCalled()
+        expect(db.getInbox(100)).toHaveLength(0)
+      }
+    )
+
     it('continues to send worker_done to a concrete terminal handle', async () => {
       setup()
       const task = db.createTask({ spec: 'work' })
diff --git a/src/main/runtime/rpc/methods/orchestration.ts b/src/main/runtime/rpc/methods/orchestration.ts
index c0849c620d5..6280921bc18 100644
--- a/src/main/runtime/rpc/methods/orchestration.ts
+++ b/src/main/runtime/rpc/methods/orchestration.ts
@@ -64,7 +64,20 @@ async function routeAllMailboxPages(
   }
 }
 
-function getLifecycleGroupRecipientError(type: 'worker_done' | 'heartbeat'): string {
+type DispatchMutationMessageType = 'worker_done' | 'heartbeat' | 'escalation' | 'decision_gate'
+
+function isDispatchMutationMessageType(
+  type: string | undefined
+): type is DispatchMutationMessageType {
+  return (
+    type === 'worker_done' ||
+    type === 'heartbeat' ||
+    type === 'escalation' ||
+    type === 'decision_gate'
+  )
+}
+
+function getLifecycleGroupRecipientError(type: DispatchMutationMessageType): string {
   return `${type} messages belong to one exact Dispatch and cannot target a group address.`
 }
 
@@ -115,11 +128,7 @@ const SendParams = z
     devMode: OptionalBoolean
   })
   .superRefine((params, ctx) => {
-    if (
-      (params.type !== 'worker_done' && params.type !== 'heartbeat') ||
-      !params.to ||
-      !isGroupAddress(params.to)
-    ) {
+    if (!isDispatchMutationMessageType(params.type) || !params.to || !isGroupAddress(params.to)) {
       return
     }
     // Why: dispatch lifecycle messages are authority/liveness signals for one coordinator; fanout would create lifecycle mail in unrelated terminals.
@@ -639,11 +648,7 @@ export const ORCHESTRATION_METHODS: RpcMethod[] = [
         const dispatch = routing.dispatchId
           ? db.getDispatchContextById(routing.dispatchId)
           : undefined
-        const dispatchMutationMessage =
-          msg.type === 'worker_done' ||
-          msg.type === 'heartbeat' ||
-          msg.type === 'escalation' ||
-          msg.type === 'decision_gate'
+        const dispatchMutationMessage = isDispatchMutationMessageType(msg.type)
         if (
           dispatchMutationMessage &&
           dispatch &&