diff --git a/gui/.eslint/i18n-allowlist.ts b/gui/.eslint/i18n-allowlist.ts
index 83974db5a8..0c0ea89c2e 100644
--- a/gui/.eslint/i18n-allowlist.ts
+++ b/gui/.eslint/i18n-allowlist.ts
@@ -97,7 +97,8 @@ export function isTechnicalLiteral(value: string): boolean {
   if (/^ocx\b/i.test(trimmed)) return true;
   if (/^codex\b/i.test(trimmed)) return true;
 
-  // HTTP headers / auth schemes
+  // HTTP protocol / headers / auth schemes
+  if (trimmed === "HTTP") return true;
   if (/^Authorization\b/i.test(trimmed)) return true;
   if (/^Bearer\b/i.test(trimmed)) return true;
   if (/^Content-Type\b/i.test(trimmed)) return true;
diff --git a/gui/src/pages/CompatibilityMatrix.tsx b/gui/src/pages/CompatibilityMatrix.tsx
index 9fcac9b129..e6084d8086 100644
--- a/gui/src/pages/CompatibilityMatrix.tsx
+++ b/gui/src/pages/CompatibilityMatrix.tsx
@@ -62,6 +62,12 @@ type ExtraVerdictPage = {
   hasMore: boolean;
 };
 
+type LoadMoreFailure = {
+  baseData: LabPageData;
+  queryKey: string;
+  message: string;
+};
+
 function localizedFetchError(e: unknown, fallback: string): string {
   if (!(e instanceof Error)) return fallback;
   const msg = e.message;
@@ -171,6 +177,11 @@ function DetailPane({
   locale: Parameters<typeof labSupplement>[0];
   onClose: () => void;
 }) {
+  const expectedEventCount = new Set([
+    ...verdict.contributingEventIds,
+    ...verdict.contradictingEventIds,
+  ]).size;
+
   return (
     <aside className="lab-detail-pane" aria-label={t("lab.detailTitle")}>
       <div className="lab-detail-head">
@@ -219,9 +230,12 @@ function DetailPane({
               </ul>
             </section>
           )}
-          {detail.events.length > 0 && (
+          {(detail.events.length > 0 || expectedEventCount > 0) && (
             <section className="lab-detail-section">
-              <h4>{t("lab.detailEvents")}</h4>
+              <h4>
+                {t("lab.detailEvents")}
+                {detail.events.length < expectedEventCount ? ` (${detail.events.length}/${expectedEventCount})` : ""}
+              </h4>
               <ul className="lab-detail-list">
                 {detail.events.map(event => (
                   <li key={event.eventId}>
@@ -264,6 +278,7 @@ export default function CompatibilityMatrix({
   const { t, locale } = useI18n();
   const [filters, setFilters] = useState<VerdictFilters>({ layer: "", verdict: "", subjectQuery: "", suiteId: "" });
   const [extraPage, setExtraPage] = useState<ExtraVerdictPage | null>(null);
+  const [loadMoreFailure, setLoadMoreFailure] = useState<LoadMoreFailure | null>(null);
   const [loadingMore, setLoadingMore] = useState(false);
   const [selectedVerdict, setSelectedVerdict] = useState<VerdictDto | null>(null);
   const [detail, setDetail] = useState<VerdictDetailData | null>(null);
@@ -293,6 +308,7 @@ export default function CompatibilityMatrix({
     loadMoreRef.current?.abort();
     loadMoreRef.current = null;
     setExtraPage(null);
+    setLoadMoreFailure(null);
     setLoadingMore(false);
   }, []);
 
@@ -329,6 +345,11 @@ export default function CompatibilityMatrix({
     && extraPage.queryKey === queryKey
     ? extraPage
     : null;
+  const visibleLoadMoreError = loadMoreFailure !== null
+    && loadMoreFailure.baseData === surface.data
+    && loadMoreFailure.queryKey === queryKey
+    ? loadMoreFailure.message
+    : null;
 
   const reportedCount = useMemo(() => {
     if (!active || !surface.data?.status.projectionAvailable) return null;
@@ -357,6 +378,7 @@ export default function CompatibilityMatrix({
     const controller = new AbortController();
     loadMoreRef.current = controller;
     const startedKey = queryKey;
+    setLoadMoreFailure(null);
     setLoadingMore(true);
     try {
       const page = await fetchMoreVerdicts(apiBase, queryFilters, cursor, controller.signal);
@@ -373,15 +395,21 @@ export default function CompatibilityMatrix({
           hasMore: page.hasMore,
         };
       });
-    } catch {
-      // Keep the current rows. The normal refresh action retries from a consistent first page.
+    } catch (e) {
+      if (!controller.signal.aborted) {
+        setLoadMoreFailure({
+          baseData,
+          queryKey: startedKey,
+          message: localizedFetchError(e, t("lab.loadFailed")),
+        });
+      }
     } finally {
       if (loadMoreRef.current === controller) {
         loadMoreRef.current = null;
         setLoadingMore(false);
       }
     }
-  }, [apiBase, loadingMore, queryFilters, queryKey, surface.data, validExtraPage]);
+  }, [apiBase, loadingMore, queryFilters, queryKey, surface.data, t, validExtraPage]);
 
   const selectVerdict = useCallback(async (verdict: VerdictDto) => {
     if (!active) return;
@@ -582,6 +610,7 @@ export default function CompatibilityMatrix({
                   </div>
                 </div>
 
+                {visibleLoadMoreError && <Notice tone="err">{visibleLoadMoreError}</Notice>}
                 {pageHasMore && (
                   <div className="lab-load-more">
                     <button type="button" className="btn btn-ghost" disabled={loadingMore} onClick={() => { void loadMore(); }}>
diff --git a/gui/tests/compatibility-lab-followup.test.tsx b/gui/tests/compatibility-lab-followup.test.tsx
new file mode 100644
index 0000000000..79f74adb49
--- /dev/null
+++ b/gui/tests/compatibility-lab-followup.test.tsx
@@ -0,0 +1,196 @@
+/** @jsxImportSource react */
+import { afterEach, beforeEach, expect, test } from "bun:test";
+import { Window } from "happy-dom";
+import { act } from "react";
+import type { Root } from "react-dom/client";
+import { LanguageProvider } from "../src/i18n/provider";
+import CompatibilityMatrix from "../src/pages/CompatibilityMatrix";
+import { clearClientResourceStoresForTests } from "../src/client-resource";
+
+const originalFetch = globalThis.fetch;
+let restoreGlobals: (() => void) | undefined;
+let previousLanguageDescriptor: PropertyDescriptor | undefined;
+let testWindow: Window;
+
+const API_BASE = "http://127.0.0.1:4096";
+
+const STATUS_AVAILABLE = {
+  projectionAvailable: true,
+  subjectCount: 1,
+  verdictCount: 1,
+  observationCount: 0,
+  eventCount: 2,
+  builtAtMs: 1_700_000_000_000,
+};
+
+const SUBJECTS = {
+  subjects: [{ subjectId: "subject-alpha", subjectKind: "protocol" }],
+  hasMore: false,
+};
+
+const SUBJECT_DETAIL = {
+  subject: {
+    subjectKind: "protocol",
+    subjectSchemaVersion: 1,
+    inboundProtocol: "openai-chat",
+  },
+};
+
+const EVENT_DETAIL = {
+  event: {
+    eventKind: "observation",
+    eventId: "e1",
+    recordedAt: 1_700_000_000_040,
+    producer: "lab",
+    producerVersion: "1",
+    subjectId: "subject-alpha",
+    evidenceLayer: "protocol_conformance",
+    suiteId: "responses-core",
+    outcome: "pass",
+    excluded: false,
+    exclusionReason: null,
+  },
+};
+
+function verdictPage(eventIds: string[]) {
+  return {
+    verdicts: [{
+      projectionKey: "k1",
+      subjectId: "subject-alpha",
+      evidenceLayer: "protocol_conformance",
+      suiteId: "responses-core",
+      suiteVersion: "1",
+      suiteManifestDigest: "digest-a",
+      projectionSpecVersion: "cl-02.v1",
+      verdict: "VERIFIED",
+      asOf: 1_700_000_000_100,
+      scenarioManifestDigests: [],
+      claimSourceDigest: null,
+      contributingEventIds: eventIds,
+      contradictingEventIds: [],
+      notes: [],
+    }],
+    hasMore: true,
+    nextCursor: "cursor-2",
+  };
+}
+
+type FetchOptions = {
+  failLoadMoreOnce?: boolean;
+  partialEvents?: boolean;
+};
+
+function installLabFetch(opts: FetchOptions = {}) {
+  const requests: string[] = [];
+  let loadMoreAttempts = 0;
+  globalThis.fetch = (async (input: RequestInfo | URL) => {
+    const url = String(input);
+    requests.push(url);
+    if (url.endsWith("/api/lab/status")) return Response.json(STATUS_AVAILABLE);
+    if (url.includes("/api/lab/verdicts")) {
+      if (url.includes("cursor=cursor-2")) {
+        loadMoreAttempts += 1;
+        if (opts.failLoadMoreOnce && loadMoreAttempts === 1) {
+          return new Response("unavailable", { status: 503 });
+        }
+        return Response.json({ verdicts: [], hasMore: false });
+      }
+      return Response.json(verdictPage(opts.partialEvents ? ["e1", "missing-event"] : ["e1"]));
+    }
+    if (url.includes("/api/lab/subjects/subject-alpha")) return Response.json(SUBJECT_DETAIL);
+    if (url.includes("/api/lab/subjects")) return Response.json(SUBJECTS);
+    if (url.includes("/api/lab/observations")) return Response.json({ observations: [], hasMore: false });
+    if (url.includes("/api/lab/events/e1")) return Response.json(EVENT_DETAIL);
+    if (url.includes("/api/lab/events/missing-event")) return new Response("gone", { status: 404 });
+    if (url.includes("/api/lab/artifacts/")) return new Response("gone", { status: 404 });
+    if (url.includes("/api/lab/production-signals")) return new Response("gone", { status: 404 });
+    return new Response("{}", { status: 404 });
+  }) as typeof fetch;
+  return { requests };
+}
+
+beforeEach(() => {
+  clearClientResourceStoresForTests();
+  testWindow = new Window({ url: "http://localhost/#models/compatibility" });
+  previousLanguageDescriptor = Object.getOwnPropertyDescriptor(globalThis.navigator, "language");
+  Object.defineProperty(globalThis.navigator, "language", { configurable: true, value: "en-US" });
+  const keys = ["document", "window", "localStorage", "IS_REACT_ACT_ENVIRONMENT"] as const;
+  const previous = Object.fromEntries(
+    keys.map(key => [key, Object.getOwnPropertyDescriptor(globalThis, key)]),
+  ) as Record<(typeof keys)[number], PropertyDescriptor | undefined>;
+  Object.defineProperties(globalThis, {
+    document: { configurable: true, value: testWindow.document },
+    window: { configurable: true, value: testWindow },
+    localStorage: { configurable: true, value: testWindow.localStorage },
+    IS_REACT_ACT_ENVIRONMENT: { configurable: true, value: true },
+  });
+  restoreGlobals = () => {
+    for (const key of keys) {
+      const descriptor = previous[key];
+      if (descriptor) Object.defineProperty(globalThis, key, descriptor);
+      else delete (globalThis as Record<string, unknown>)[key];
+    }
+    if (previousLanguageDescriptor) {
+      Object.defineProperty(globalThis.navigator, "language", previousLanguageDescriptor);
+    }
+  };
+});
+
+afterEach(() => {
+  restoreGlobals?.();
+  globalThis.fetch = originalFetch;
+  clearClientResourceStoresForTests();
+  testWindow.close();
+});
+
+async function waitFor(predicate: () => boolean, timeoutMs = 3000): Promise<void> {
+  const start = Date.now();
+  while (!predicate()) {
+    if (Date.now() - start > timeoutMs) throw new Error("waitFor timed out");
+    await act(async () => {
+      await new Promise<void>(resolve => testWindow.setTimeout(resolve, 10));
+    });
+  }
+}
+
+async function renderMatrix(): Promise<{ root: Root; container: HTMLDivElement }> {
+  const { createRoot } = await import("react-dom/client");
+  const container = testWindow.document.createElement("div");
+  testWindow.document.body.appendChild(container);
+  const root = createRoot(container);
+  await act(async () => {
+    root.render(<LanguageProvider><CompatibilityMatrix apiBase={API_BASE} /></LanguageProvider>);
+  });
+  return { root, container };
+}
+
+test("load-more failures stay visible and a retry can recover", async () => {
+  const { requests } = installLabFetch({ failLoadMoreOnce: true });
+  const { root, container } = await renderMatrix();
+  await waitFor(() => container.querySelector(".lab-load-more button") !== null);
+  const button = container.querySelector(".lab-load-more button") as HTMLButtonElement;
+  await act(async () => { button.click(); });
+  await waitFor(() => container.querySelector(".notice-err")?.textContent?.includes(String(503)) ?? false);
+  expect(container.textContent).toContain("Verified");
+  expect(container.querySelector(".lab-load-more button")).not.toBeNull();
+
+  await act(async () => {
+    (container.querySelector(".lab-load-more button") as HTMLButtonElement).click();
+  });
+  await waitFor(() => container.querySelector(".notice-err") === null);
+  await waitFor(() => container.querySelector(".lab-load-more button") === null);
+  expect(requests.filter(url => url.includes("/api/lab/verdicts") && url.includes("cursor=cursor-2"))).toHaveLength(2);
+  expect(container.textContent).toContain("Verified");
+  await act(async () => root.unmount());
+});
+
+test("verdict detail reports when referenced evidence events are only partially available", async () => {
+  installLabFetch({ partialEvents: true });
+  const { root, container } = await renderMatrix();
+  await waitFor(() => container.querySelector('button[data-verdict-detail="k1"]') !== null);
+  const button = container.querySelector('button[data-verdict-detail="k1"]') as HTMLButtonElement;
+  await act(async () => { button.click(); });
+  await waitFor(() => container.querySelector(".lab-detail-pane")?.textContent?.includes("Evidence events (1/2)") ?? false);
+  expect(container.querySelector(".lab-detail-pane")?.textContent).toContain("Evidence events (1/2)");
+  await act(async () => root.unmount());
+});