diff --git a/apps/control-station/src/components/laboratory/useRecordedEvidencePlayback.ts b/apps/control-station/src/components/laboratory/useRecordedEvidencePlayback.ts
index 95e660d..1ad45a0 100644
--- a/apps/control-station/src/components/laboratory/useRecordedEvidencePlayback.ts
+++ b/apps/control-station/src/components/laboratory/useRecordedEvidencePlayback.ts
@@ -40,6 +40,23 @@ export function advanceRecordedEvidencePlayback(
   return { ...playback, currentSeconds: clampRecordedEvidenceSeconds(next, range) };
 }
 
+export function synchronizeRecordedEvidencePlayback(
+  current: RecordedObservationPlayback,
+  observed: RecordedObservationPlayback,
+  range: RecordedEvidencePlaybackRange,
+): RecordedObservationPlayback {
+  const currentSeconds = clampRecordedEvidenceSeconds(observed.currentSeconds, range);
+  return {
+    ...current,
+    currentSeconds,
+    // The transport button owns play/pause intent. A native frame callback may
+    // still report the previous media state immediately after an operator
+    // command, so it must not restart playback. The sealed end is the only
+    // media-clock transition allowed to stop the shared LAB clock.
+    playing: currentSeconds >= range.endSeconds ? false : current.playing,
+  };
+}
+
 export function useRecordedEvidencePlayback(
   range: RecordedEvidencePlaybackRange | null,
   { clock = "animation" }: { clock?: "animation" | "external" } = {},
@@ -106,11 +123,7 @@ export function useRecordedEvidencePlayback(
 
   const synchronize = useCallback((next: RecordedObservationPlayback) => {
     if (!validRange(range) || !Number.isFinite(next.currentSeconds)) return;
-    setPlayback((current) => ({
-      ...current,
-      currentSeconds: clampRecordedEvidenceSeconds(next.currentSeconds, range),
-      playing: next.playing,
-    }));
+    setPlayback((current) => synchronizeRecordedEvidencePlayback(current, next, range));
   }, [range]);
 
   return useMemo(() => ({
diff --git a/apps/control-station/src/styles/m4-replay-threat.css b/apps/control-station/src/styles/m4-replay-threat.css
index 1a0af6b..7e575bc 100644
--- a/apps/control-station/src/styles/m4-replay-threat.css
+++ b/apps/control-station/src/styles/m4-replay-threat.css
@@ -219,10 +219,13 @@
 
 .m4-replay-threat-visual__overlay {
   box-sizing: border-box;
+  min-width: 0;
   align-items: stretch;
-  width: min(22rem, calc(33.333333% - 0.8rem));
-  grid-template-columns: minmax(0, 1fr);
+  width: max-content;
+  max-width: calc(var(--m4-replay-threat-overlay-pane-width, 100%) - 1.2rem);
+  grid-template-columns: minmax(0, max-content);
   gap: 0.3rem;
+  overflow: hidden;
   background: transparent;
   padding: 0;
   backdrop-filter: none;
@@ -235,9 +238,17 @@
   backdrop-filter: blur(var(--nodedc-blur-control));
 }
 
+.m4-replay-threat-visual__overlay span,
+.m4-replay-threat-visual__overlay strong,
+.m4-replay-threat-visual__overlay small {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
 @media (max-width: 900px) {
   .m4-replay-threat-visual__overlay {
-    width: min(22rem, calc(100% - 1.2rem));
+    max-width: calc(100% - 1.2rem);
   }
 }
 
diff --git a/apps/control-station/src/workspaces/laboratory/M4ReplayThreatVisual.tsx b/apps/control-station/src/workspaces/laboratory/M4ReplayThreatVisual.tsx
index 0181887..964740c 100644
--- a/apps/control-station/src/workspaces/laboratory/M4ReplayThreatVisual.tsx
+++ b/apps/control-station/src/workspaces/laboratory/M4ReplayThreatVisual.tsx
@@ -1,4 +1,4 @@
-import { useEffect, useMemo, useRef, useState } from "react";
+import { useEffect, useMemo, useRef, useState, type CSSProperties } from "react";
 import {
   Button,
   Icon,
@@ -442,8 +442,17 @@ export function M4ReplayThreatVisual({
 
   const trailingActions = !splitView && spatialMode ? resetSpatialView : null;
 
+  const overlayPanePercent = splitView && splitOrientation === "vertical"
+    ? splitPrimarySize
+    : 100;
+
   const overlay = metadata.timeline && frame ? (
-    <div className="l3-visual-audit__overlay m4-replay-threat-visual__overlay">
+    <div
+      className="l3-visual-audit__overlay m4-replay-threat-visual__overlay"
+      style={{
+        "--m4-replay-threat-overlay-pane-width": `${overlayPanePercent}%`,
+      } as CSSProperties}
+    >
       <div>
         <span>RAVNOVES00 · recorded realtime</span>
         <strong>frame {frame.sequence + 1}/{metadata.timeline.frameCount}</strong>
diff --git a/apps/control-station/test/m4ReplayThreat.test.mjs b/apps/control-station/test/m4ReplayThreat.test.mjs
index 373a8cf..7128795 100644
--- a/apps/control-station/test/m4ReplayThreat.test.mjs
+++ b/apps/control-station/test/m4ReplayThreat.test.mjs
@@ -12,6 +12,7 @@ let fetchM4ThreatTimelineChunk;
 let selectM4ThreatTimelineFrame;
 let selectM4ThreatTimelineSequence;
 let advanceRecordedEvidencePlayback;
+let synchronizeRecordedEvidencePlayback;
 let m4ThreatChunkWindowStarts;
 let buildM4LocalSurface;
 
@@ -31,7 +32,10 @@ before(async () => {
     selectM4ThreatTimelineFrame,
     selectM4ThreatTimelineSequence,
   } = await server.ssrLoadModule("/src/core/laboratory/m4ReplayThreat.ts"));
-  ({ advanceRecordedEvidencePlayback } = await server.ssrLoadModule(
+  ({
+    advanceRecordedEvidencePlayback,
+    synchronizeRecordedEvidencePlayback,
+  } = await server.ssrLoadModule(
     "/src/components/laboratory/useRecordedEvidencePlayback.ts",
   ));
   ({ m4ThreatChunkWindowStarts } = await server.ssrLoadModule(
@@ -391,6 +395,26 @@ test("recorded evidence clock advances by selected rate and stops at the sealed
   );
 });
 
+test("recorded VIDEO clock cannot reverse an explicit operator pause", () => {
+  const range = { startSeconds: 10, endSeconds: 20 };
+  assert.deepEqual(
+    synchronizeRecordedEvidencePlayback(
+      { currentSeconds: 15, playing: false, rate: 2 },
+      { currentSeconds: 15.1, playing: true, rate: 1 },
+      range,
+    ),
+    { currentSeconds: 15.1, playing: false, rate: 2 },
+  );
+  assert.deepEqual(
+    synchronizeRecordedEvidencePlayback(
+      { currentSeconds: 19.9, playing: true, rate: 1 },
+      { currentSeconds: 20, playing: false, rate: 1 },
+      range,
+    ),
+    { currentSeconds: 20, playing: false, rate: 1 },
+  );
+});
+
 test("M4.6 viewer keeps media and spatial panes on one playback clock", async () => {
   const [visual, visualCss, imageScene, videoScene, metricScene] = await Promise.all([
     readFile(new URL("../src/workspaces/laboratory/M4ReplayThreatVisual.tsx", import.meta.url), "utf8"),
@@ -434,8 +458,10 @@ test("M4.6 viewer keeps media and spatial panes on one playback clock", async ()
   assert.match(visualCss, /width: 33\.333333%/);
   assert.match(visualCss, /flex-flow: column nowrap/);
   assert.match(visualCss, /m4-replay-threat-visual__overlay > div/);
-  assert.match(visualCss, /grid-template-columns: minmax\(0, 1fr\)/);
-  assert.match(visualCss, /width: min\(22rem, calc\(33\.333333% - 0\.8rem\)\)/);
+  assert.match(visualCss, /grid-template-columns: minmax\(0, max-content\)/);
+  assert.match(visualCss, /width: max-content/);
+  assert.match(visualCss, /--m4-replay-threat-overlay-pane-width/);
+  assert.match(visualCss, /white-space: nowrap/);
   assert.match(visualCss, /laboratory-metric-evidence-scene__legend/);
   assert.match(visualCss, /bottom: auto/);
   assert.match(videoScene, /<RecordedFmp4Player/);