diff --git a/backend/src/common/body-parsers.spec.ts b/backend/src/common/body-parsers.spec.ts
index d64b859..e54019b 100644
--- a/backend/src/common/body-parsers.spec.ts
+++ b/backend/src/common/body-parsers.spec.ts
@@ -93,6 +93,9 @@ describe('createJsonBodyParser', () => {
       '/api/voice/extract/extra',
       '/api/voice',
       '/voice/extract',
+      // Express ignores one trailing slash, not two — this one never routes, so it must
+      // not get the large parser either.
+      '/api/voice/extract//',
     ]) {
       const res = await request(buildApp()).post(path).send(bodyOfKb(300));
       expect(res.status).toBe(413);
diff --git a/backend/src/common/body-parsers.ts b/backend/src/common/body-parsers.ts
index 97278da..9f40162 100644
--- a/backend/src/common/body-parsers.ts
+++ b/backend/src/common/body-parsers.ts
@@ -31,7 +31,10 @@ export const VOICE_BODY_LIMIT = '10mb';
  * recording — a failure that looks like a broken microphone, not a routing detail.
  */
 function isVoiceExtractPath(path: string): boolean {
-  return path.toLowerCase().replace(/\/+$/, '') === VOICE_EXTRACT_PATH;
+  // Exactly one trailing slash, because that is exactly what Express ignores. Stripping
+  // every trailing slash would hand the 10 MB parser to `/api/voice/extract//`, which
+  // buffers the body and then 404s — memory spent on a request that never routes.
+  return path.toLowerCase().replace(/\/$/, '') === VOICE_EXTRACT_PATH;
 }
 
 export function createJsonBodyParser(): RequestHandler {
diff --git a/frontend/src/components/ui/treatment/TreatmentWorkspace.tsx b/frontend/src/components/ui/treatment/TreatmentWorkspace.tsx
index 0aca70e..c50978a 100644
--- a/frontend/src/components/ui/treatment/TreatmentWorkspace.tsx
+++ b/frontend/src/components/ui/treatment/TreatmentWorkspace.tsx
@@ -2006,6 +2006,14 @@ export function TreatmentWorkspace({
         void (async () => {
           try {
             const saved = await persistDraft({ force: true });
+            // persistDraft returns a *preview* treatment rather than saving when the
+            // details are not persistable — one blank detail, the kind the workspace opens
+            // with, is enough. A preview's detail id falls back to the client id, so
+            // posting lab cases against it would send the server an id it has never seen
+            // and fail the whole save. Check what came back, not the precondition, so this
+            // holds for every early return persistDraft has.
+            const savedDetail = saved.details.find((d) => d.clientId === detail.clientId);
+            if (!savedDetail?.id || savedDetail.id === detail.clientId) return;
             await persistLabCases(saved, updatedLabCases);
           } catch (error: unknown) {
             showError(getUserFacingError(error, tErrors, t('errorSaveLabShipments')));
diff --git a/frontend/src/lib/voice/useVoiceCapture.ts b/frontend/src/lib/voice/useVoiceCapture.ts
index f17a74e..7882db3 100644
--- a/frontend/src/lib/voice/useVoiceCapture.ts
+++ b/frontend/src/lib/voice/useVoiceCapture.ts
@@ -139,8 +139,16 @@ export function useVoiceCapture({
   );
 
   const stop = useCallback(() => {
+    // No recorder means nothing will fire `onstop`, so nothing else will move the phase.
+    // Optional-chaining into a no-op here left the bar recording forever with a running
+    // timer, and only Cancel could get out of it.
+    if (!recorderRef.current) {
+      teardown();
+      setPhase('idle');
+      return;
+    }
     try {
-      recorderRef.current?.stop();
+      recorderRef.current.stop();
     } catch {
       teardown();
       setPhase('idle');
@@ -150,7 +158,9 @@ export function useVoiceCapture({
   const onStart = useCallback(() => {
     if (phase !== 'idle' || startingRef.current) return;
     if (!isMediaRecorderSupported()) {
-      onError(clientError('VOICE_MIC_DENIED'));
+      // Not a permission problem: this browser cannot record at all. Saying "microphone
+      // denied" sends the clinician to hunt for a permission nothing ever asked for.
+      onError(clientError('VOICE_UNSUPPORTED_FORMAT'));
       return;
     }
 
@@ -177,8 +187,9 @@ export function useVoiceCapture({
 
         const mimeType = pickRecordingMimeType();
         if (mimeType === null) {
+          // The browser records, but in no container the transcription API accepts.
           stream.getTracks().forEach((track) => track.stop());
-          onError(clientError('VOICE_MIC_DENIED'));
+          onError(clientError('VOICE_UNSUPPORTED_FORMAT'));
           return;
         }
 
@@ -226,7 +237,9 @@ export function useVoiceCapture({
         // recording indicator stays lit until the workspace unmounts.
         teardown();
         setPhase('idle');
-        onError(clientError('VOICE_MIC_DENIED'));
+        // The permission was already granted by this point — what failed is the recorder
+        // itself, so this is "this browser cannot record", not "you denied the mic".
+        onError(clientError('VOICE_UNSUPPORTED_FORMAT'));
       } finally {
         startingRef.current = false;
       }