diff --git a/.sandcastle/issue-source.ts b/.sandcastle/issue-source.ts
index 5175a67..6b33674 100644
--- a/.sandcastle/issue-source.ts
+++ b/.sandcastle/issue-source.ts
@@ -12,6 +12,20 @@ import { READY_LABEL, type Issue, type ReviewOutput } from "./reduce.ts";
 
 const exec = promisify(execFile);
 
+/**
+ * Render a structured review verdict as plain markdown, for postPrReview's
+ * final fallback (a plain PR comment) when GitHub's formal review API is
+ * unavailable (self-review restriction — see postPrReview).
+ */
+export function formatReviewAsComment(output: ReviewOutput): string {
+  const header = `**AI review: ${output.verdict}**\n\n${output.summary}`;
+  if (output.comments.length === 0) return header;
+  const commentsBlock = output.comments
+    .map((c) => `**${c.path}:${c.line}** — ${c.body}`)
+    .join("\n\n");
+  return `${header}\n\n---\n${commentsBlock}`;
+}
+
 /** Parse "Blocked by #N" references from an issue body (one or many). */
 export function parseBlockedBy(body: string): number[] {
   const idx = body.search(/blocked\s+by\b/i);
@@ -228,7 +242,16 @@ export class IssueSource {
   /**
    * Post a REQUEST_CHANGES review on the PR for the given issue.
    * Uses the GitHub API to attach the structured verdict + filtered inline comments.
-   * Best-effort: if inline-comment posting fails, falls back to a plain PR comment.
+   * Best-effort, two-stage fallback:
+   *   1. inline comments may fail when lines are no longer in the diff — retry
+   *      as a plain top-level review (no inline comments).
+   *   2. GitHub rejects REQUEST_CHANGES reviews from a PR's OWN AUTHOR
+   *      ("Review Can not request changes on your own pull request", HTTP 422)
+   *      — the normal case here, since this orchestrator's GH_TOKEN both opens
+   *      the PR and posts its AI review. A plain PR comment carries the same
+   *      feedback without that restriction, so it is the final fallback rather
+   *      than letting the verdict go unposted (confirmed live: both the inline
+   *      and body-only review attempts hit the identical 422 in that case).
    */
   async postPrReview(issueId: number, output: ReviewOutput): Promise<void> {
     const { stdout: prJson } = await this.gh([
@@ -254,16 +277,23 @@ export class IssueSource {
         ["api", `repos/{owner}/{repo}/pulls/${prInfo.number}/reviews`, "--method", "POST", "--input", "-"],
         JSON.stringify(reviewBody),
       );
+      return;
     } catch (err) {
-      // Inline comments may fail when lines are no longer in the diff; fall back to a
-      // plain top-level review without inline comments so the verdict is still visible.
       console.warn(`[issue-source] inline review post failed — falling back to body-only review:`, err);
+    }
+
+    try {
       const bodyOnly = { ...reviewBody, comments: [] };
       await this.ghWithInput(
         ["api", `repos/{owner}/{repo}/pulls/${prInfo.number}/reviews`, "--method", "POST", "--input", "-"],
         JSON.stringify(bodyOnly),
       );
+      return;
+    } catch (err) {
+      console.warn(`[issue-source] body-only review post also failed — falling back to a plain PR comment:`, err);
     }
+
+    await this.comment(issueId, formatReviewAsComment(output));
   }
 
   /** Open a PR for an already-pushed head branch. Returns the PR URL. */
diff --git a/.sandcastle/reduce.test.ts b/.sandcastle/reduce.test.ts
index 64a6709..711e49e 100644
--- a/.sandcastle/reduce.test.ts
+++ b/.sandcastle/reduce.test.ts
@@ -9,7 +9,7 @@
 import { test } from "node:test";
 import assert from "node:assert/strict";
 import { reduce, READY_LABEL, IN_PROGRESS_LABEL, IN_REVIEW_LABEL, reviewVerdict, reconcileFromLabels, type State, type CiStatus, type Pr, type ReviewOutput } from "./reduce.ts";
-import { parseBlockedBy } from "./issue-source.ts";
+import { parseBlockedBy, formatReviewAsComment } from "./issue-source.ts";
 import { sweepOrphanedSandboxes, ensureSandboxNetwork, parseConcurrency, withRetry, resetAgentBranch, refreshBase, validateSignature, classifyDelivery, parseSmeeEvent, parseOrchEnv, resolveCredentials, resolveRunMode, resolveDockerHost } from "./main.ts";
 import { createHmac } from "node:crypto";
 import { SANDBOX_LABEL, PROJECT_LABEL_KEY, deriveProject } from "./sandbox-runner.ts";
@@ -105,6 +105,40 @@ test("parseBlockedBy: stops at next markdown section", () => {
   );
 });
 
+// ─── formatReviewAsComment ───────────────────────────────────────────────────
+
+test("formatReviewAsComment: no comments — just verdict and summary", () => {
+  const rendered = formatReviewAsComment({ verdict: "pass", summary: "Looks good.", comments: [] });
+  assert.equal(rendered, "**AI review: pass**\n\nLooks good.");
+});
+
+test("formatReviewAsComment: includes each comment with path:line", () => {
+  const rendered = formatReviewAsComment({
+    verdict: "changes-requested",
+    summary: "One issue found.",
+    comments: [{ path: "src/foo.ts", line: 42, body: "This is wrong." }],
+  });
+  assert.equal(
+    rendered,
+    "**AI review: changes-requested**\n\nOne issue found.\n\n---\n**src/foo.ts:42** — This is wrong.",
+  );
+});
+
+test("formatReviewAsComment: multiple comments joined with blank lines", () => {
+  const rendered = formatReviewAsComment({
+    verdict: "changes-requested",
+    summary: "Two issues.",
+    comments: [
+      { path: "a.ts", line: 1, body: "first" },
+      { path: "b.ts", line: 2, body: "second" },
+    ],
+  });
+  assert.equal(
+    rendered,
+    "**AI review: changes-requested**\n\nTwo issues.\n\n---\n**a.ts:1** — first\n\n**b.ts:2** — second",
+  );
+});
+
 // ─── Dependency blocking (isReady + Tick) ────────────────────────────────────
 
 test("issue with no blockers (blockedBy: []) behaves as before", () => {