diff --git a/src/review/enrichment-wire.ts b/src/review/enrichment-wire.ts
index 8210596cb7..ab5a66f668 100644
--- a/src/review/enrichment-wire.ts
+++ b/src/review/enrichment-wire.ts
@@ -108,7 +108,11 @@ export async function buildReviewEnrichment(
           ? ENRICHMENT_SYSTEM_SUFFIX
           : "",
     };
-  } catch {
+  } catch (error) {
+    // Surface the failure (#5 review observability): the REES enrichment call can fail (timeout / network / parse)
+    // and the review then silently proceeds without the brief. ERROR level so the central Sentry forwarder captures
+    // a broken/slow REES backend instead of it degrading invisibly.
+    console.error(JSON.stringify({ level: "error", event: "review_context_fetch_failed", repository: input.repoFullName, contextType: "enrichment", message: String(error).slice(0, 200) }));
     return undefined; // timeout / network / parse ⇒ fail-safe; review proceeds without the brief
   }
 }
diff --git a/src/review/inline-comments.ts b/src/review/inline-comments.ts
index 7c1579db52..7ddd0d6a8b 100644
--- a/src/review/inline-comments.ts
+++ b/src/review/inline-comments.ts
@@ -118,7 +118,9 @@ export async function postInlineReviewComments(
     await createPullRequestReviewComments(env, args.installationId, args.repoFullName, args.pullNumber, args.commitId, comments, args.mode);
     return { posted: comments.length };
   } catch (error) {
-    console.warn(JSON.stringify({ level: "warn", event: "inline_comments_post_failed", repository: args.repoFullName, pullNumber: args.pullNumber, count: comments.length, error: errorMessage(error) }));
+    // ERROR level (#5 review observability) so the central Sentry forwarder captures a failing inline-comment post
+    // (auth/permission/422) — it degrades silently (gate unaffected) and was otherwise invisible at warn.
+    console.error(JSON.stringify({ level: "error", event: "inline_comments_post_failed", repository: args.repoFullName, pullNumber: args.pullNumber, count: comments.length, error: errorMessage(error) }));
     return { posted: 0 };
   }
 }
diff --git a/src/review/rag.ts b/src/review/rag.ts
index 26420af97f..afd34b3130 100644
--- a/src/review/rag.ts
+++ b/src/review/rag.ts
@@ -407,7 +407,10 @@ export async function retrieveContext(
     );
     return out;
   } catch (error) {
-    console.log(JSON.stringify({ ev: "rag_retrieve_error", message: String(error).slice(0, 200) }));
+    // ERROR level (#5 review observability): emit so the central Sentry forwarder captures a broken RAG backend
+    // (qdrant/embedder down) — retrieval degrades the review to diff-only, and this was previously a no-`level`
+    // console.log invisible to Sentry. Keeps the `ev` tag for log continuity.
+    console.error(JSON.stringify({ level: "error", event: "review_context_fetch_failed", contextType: "rag", ev: "rag_retrieve_error", message: String(error).slice(0, 200) }));
     return "";
   }
 }
diff --git a/test/unit/enrichment-wire.test.ts b/test/unit/enrichment-wire.test.ts
index f9583ea08a..361bf1170b 100644
--- a/test/unit/enrichment-wire.test.ts
+++ b/test/unit/enrichment-wire.test.ts
@@ -99,6 +99,17 @@ describe("buildReviewEnrichment", () => {
     ).toBeUndefined();
   });
 
+  it("undefined on a fetch error (network/timeout) and surfaces it at ERROR for Sentry (#5)", async () => {
+    const errSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    globalThis.fetch = vi.fn(async () => {
+      throw new Error("network down");
+    }) as unknown as typeof fetch;
+    expect(await buildReviewEnrichment(env({ REES_URL: "https://r" }), input)).toBeUndefined();
+    // A broken/slow REES backend now surfaces at level:error (central Sentry forwarder) instead of degrading silently.
+    expect(errSpy.mock.calls.some((c) => String(c[0]).includes("review_context_fetch_failed") && String(c[0]).includes('"contextType":"enrichment"'))).toBe(true);
+    errSpy.mockRestore();
+  });
+
   it("undefined on an empty promptSection (no findings)", async () => {
     globalThis.fetch = vi.fn(
       async () =>
diff --git a/test/unit/inline-comments.test.ts b/test/unit/inline-comments.test.ts
index 37228b1767..45d3ef4e93 100644
--- a/test/unit/inline-comments.test.ts
+++ b/test/unit/inline-comments.test.ts
@@ -118,13 +118,17 @@ describe("postInlineReviewComments (#inline-comments, fail-safe)", () => {
     expect(calls[0]?.body).toMatchObject({ event: "COMMENT", commit_id: "headsha", comments: [{ path: "src/a.ts", line: 2, side: "RIGHT", body: "**Nit:** guard this" }] });
   });
 
-  it("swallows an API error (the gate is never affected) and reports 0 posted", async () => {
+  it("swallows an API error (the gate is never affected), reports 0 posted, and surfaces it at ERROR for Sentry (#5)", async () => {
+    const errSpy = vi.spyOn(console, "error").mockImplementation(() => {});
     vi.stubGlobal("fetch", async (input: RequestInfo | URL) => {
       const url = input.toString();
       if (url.includes("/access_tokens")) return Response.json({ token: "t" });
       return new Response("boom", { status: 500 }); // /reviews → non-2xx → octokit throws → caught
     });
     expect(await postInlineReviewComments(envWithKey(), { ...base, commitId: "headsha", findings })).toEqual({ posted: 0 });
+    // The failure is now emitted at level:error so the central Sentry forwarder captures it (was an invisible warn).
+    expect(errSpy.mock.calls.some((c) => String(c[0]).includes("inline_comments_post_failed") && String(c[0]).includes('"level":"error"'))).toBe(true);
+    errSpy.mockRestore();
   });
 });
 
diff --git a/test/unit/rag-wiring.test.ts b/test/unit/rag-wiring.test.ts
index 2bcd09a449..5968a2068a 100644
--- a/test/unit/rag-wiring.test.ts
+++ b/test/unit/rag-wiring.test.ts
@@ -156,10 +156,14 @@ describe("buildReviewRagContext: retrieval wiring + fail-safe", () => {
     expect(vec.query).not.toHaveBeenCalled();
   });
 
-  it("fail-safe: a THROWING vector query degrades to empty context (never throws)", async () => {
+  it("fail-safe: a THROWING vector query degrades to empty context (never throws) + surfaces it at ERROR for Sentry (#5)", async () => {
+    const errSpy = vi.spyOn(console, "error").mockImplementation(() => {});
     const vec = { ...vectorizeStub(), query: vi.fn(async () => { throw new Error("vectorize down"); }) };
     const env = createTestEnv({ DB: ragDbStub(), VECTORIZE: vec as unknown as Vectorize, AI: aiStub() as unknown as Ai });
     await expect(buildReviewRagContext(env, { repoFullName: "acme/rag-throw-1", files: changedFiles })).resolves.toBe("");
+    // A broken RAG backend now surfaces at level:error (central Sentry forwarder) instead of degrading invisibly.
+    expect(errSpy.mock.calls.some((c) => String(c[0]).includes("review_context_fetch_failed") && String(c[0]).includes('"contextType":"rag"'))).toBe(true);
+    errSpy.mockRestore();
   });
 
   it("fail-safe: no changed files → empty context, no adapter use", async () => {