diff --git a/frontend/src/components/test-detail/TeamTabs.tsx b/frontend/src/components/test-detail/TeamTabs.tsx
index c2baed2..513e015 100644
--- a/frontend/src/components/test-detail/TeamTabs.tsx
+++ b/frontend/src/components/test-detail/TeamTabs.tsx
@@ -189,6 +189,12 @@ export default function TeamTabs({
     ? blueDraft.detection_result === "detected" || blueDraft.detection_result === "partially_detected"
     : test.detection_result === "detected" || test.detection_result === "partially_detected";
 
+  // Containment Time only makes sense when something was actually contained —
+  // "Not Contained" has no containment moment to record.
+  const isContained = canEditBlue
+    ? blueDraft.containment_result === "contained" || blueDraft.containment_result === "partially_contained"
+    : test.containment_result === "contained" || test.containment_result === "partially_contained";
+
   // Hint messages shown to operators when editing is locked
   const redLockedHint =
     test.state === "draft" && role === "red_tech"
@@ -520,7 +526,9 @@ export default function TeamTabs({
         </div>
       )}
 
-      {/* Detection & Containment times — only when detected/partially_detected */}
+      {/* Detection & Containment times — Detection Time whenever detected;
+          Containment Time only when something was actually contained —
+          "Not Contained" has no containment moment to record. */}
       {isDetected && (
         <div className="grid grid-cols-2 gap-4">
           <div>
@@ -541,24 +549,26 @@ export default function TeamTabs({
               </p>
             )}
           </div>
-          <div>
-            <label className="mb-1.5 block text-sm font-medium text-gray-300">
-              Containment Time (UTC) <span className="text-red-400">*</span>
-            </label>
-            {canEditBlue ? (
-              <input
-                type="datetime-local"
-                required
-                value={blueDraft.containment_time}
-                onChange={(e) => onBlueFieldChange("containment_time", e.target.value)}
-                className="w-full rounded-lg border border-gray-700 bg-gray-800 px-3 py-2 text-sm text-gray-200 focus:border-indigo-500 focus:outline-none focus:ring-1 focus:ring-indigo-500"
-              />
-            ) : (
-              <p className="text-sm text-gray-400">
-                {test.containment_time ? new Date(test.containment_time + "Z").toUTCString().replace(" GMT", " UTC") : "—"}
-              </p>
-            )}
-          </div>
+          {isContained && (
+            <div>
+              <label className="mb-1.5 block text-sm font-medium text-gray-300">
+                Containment Time (UTC) <span className="text-red-400">*</span>
+              </label>
+              {canEditBlue ? (
+                <input
+                  type="datetime-local"
+                  required
+                  value={blueDraft.containment_time}
+                  onChange={(e) => onBlueFieldChange("containment_time", e.target.value)}
+                  className="w-full rounded-lg border border-gray-700 bg-gray-800 px-3 py-2 text-sm text-gray-200 focus:border-indigo-500 focus:outline-none focus:ring-1 focus:ring-indigo-500"
+                />
+              ) : (
+                <p className="text-sm text-gray-400">
+                  {test.containment_time ? new Date(test.containment_time + "Z").toUTCString().replace(" GMT", " UTC") : "—"}
+                </p>
+              )}
+            </div>
+          )}
         </div>
       )}
 
diff --git a/frontend/src/pages/TestDetailPage.tsx b/frontend/src/pages/TestDetailPage.tsx
index f493a89..852fdd1 100644
--- a/frontend/src/pages/TestDetailPage.tsx
+++ b/frontend/src/pages/TestDetailPage.tsx
@@ -446,7 +446,17 @@ export default function TestDetailPage() {
   };
 
   const handleBlueFieldChange = (field: string, value: string) => {
-    setBlueDraft((prev) => ({ ...prev, [field]: value }));
+    setBlueDraft((prev) => {
+      const next = { ...prev, [field]: value };
+      // Containment Time only applies when something was actually
+      // contained — clear a stale value left over from a previous
+      // "Contained"/"Partially Contained" selection so it doesn't get
+      // silently resubmitted once the field is hidden again.
+      if (field === "containment_result" && value !== "contained" && value !== "partially_contained") {
+        next.containment_time = "";
+      }
+      return next;
+    });
   };
 
   const handleUploadEvidence = async (file: File, team: TeamSide) => {
@@ -624,8 +634,9 @@ export default function TestDetailPage() {
                 <button
                   onClick={() => {
                     const isDetected = blueDraft.detection_result === "detected" || blueDraft.detection_result === "partially_detected";
+                    const isContained = blueDraft.containment_result === "contained" || blueDraft.containment_result === "partially_contained";
                     if (isDetected && !blueDraft.detection_time) { showToast("Detection Time is required", "error"); return; }
-                    if (isDetected && !blueDraft.containment_time) { showToast("Containment Time is required", "error"); return; }
+                    if (isContained && !blueDraft.containment_time) { showToast("Containment Time is required", "error"); return; }
                     saveBlueMutation.mutate();
                   }}
                   disabled={saveBlueMutation.isPending}