diff --git a/cmd/review-bot/main.go b/cmd/review-bot/main.go
index d5e4734..d98e3db 100644
--- a/cmd/review-bot/main.go
+++ b/cmd/review-bot/main.go
@@ -327,7 +327,7 @@ func main() {
 			// In shared-token mode, skip superseding to avoid clobbering sibling reviews.
 			sharedToken := hasSharedToken(existingReviews, sentinel)
 			if !sharedToken {
-				existing := findOwnReview(existingReviews, sentinel)
+				existing := findOwnReviewStrict(existingReviews, sentinel, *reviewerName)
 				if existing != nil {
 					commentID, err := giteaClient.GetTimelineReviewCommentID(ctx, owner, repoName, prNumber, sentinel)
 					if err != nil {
@@ -522,9 +522,13 @@ func buildSupersededBody(originalBody, commitSHA, sentinel string) string {
 	var sb strings.Builder
 	sb.WriteString("~~Original review~~\n\n")
 	sb.WriteString("**Superseded** \u2014 see current review for up-to-date findings.\n\n")
-	sb.WriteString("<details><summary>Previous findings (commit ")
-	sb.WriteString(shortSHA)
-	sb.WriteString(")</summary>\n\n")
+	if shortSHA != "" {
+		sb.WriteString("<details><summary>Previous findings (commit ")
+		sb.WriteString(shortSHA)
+		sb.WriteString(")</summary>\n\n")
+	} else {
+		sb.WriteString("<details><summary>Previous findings</summary>\n\n")
+	}
 	sb.WriteString(originalBody)
 	sb.WriteString("\n\n</details>\n\n")
 	sb.WriteString(sentinel)
@@ -574,10 +578,40 @@ func extractSentinelName(body string) string {
 
 // findOwnReview locates a review matching the given sentinel in its body.
 func findOwnReview(reviews []gitea.Review, sentinel string) *gitea.Review {
+	var best *gitea.Review
 	for i := range reviews {
-		if strings.Contains(reviews[i].Body, sentinel) {
-			return &reviews[i]
+		if !strings.Contains(reviews[i].Body, sentinel) {
+			continue
+		}
+		// Skip superseded reviews (they contain our sentinel in the collapsed body)
+		if strings.Contains(reviews[i].Body, "~~Original review~~") {
+			continue
+		}
+		// Take the highest ID (most recent)
+		if best == nil || reviews[i].ID > best.ID {
+			best = &reviews[i]
 		}
 	}
-	return nil
+	return best
+}
+
+// findOwnReviewStrict is like findOwnReview but also verifies the review
+// was posted by the expected user (defense-in-depth against sentinel injection).
+func findOwnReviewStrict(reviews []gitea.Review, sentinel, expectedLogin string) *gitea.Review {
+	var best *gitea.Review
+	for i := range reviews {
+		if !strings.Contains(reviews[i].Body, sentinel) {
+			continue
+		}
+		if strings.Contains(reviews[i].Body, "~~Original review~~") {
+			continue
+		}
+		if expectedLogin != "" && reviews[i].User.Login != expectedLogin {
+			continue
+		}
+		if best == nil || reviews[i].ID > best.ID {
+			best = &reviews[i]
+		}
+	}
+	return best
 }
diff --git a/cmd/review-bot/main_test.go b/cmd/review-bot/main_test.go
index 9944185..d812ea2 100644
--- a/cmd/review-bot/main_test.go
+++ b/cmd/review-bot/main_test.go
@@ -140,6 +140,32 @@ func TestFindOwnReview(t *testing.T) {
 			sentinel: "<!-- review-bot:sonnet -->",
 			wantID:   20,
 		},
+		{
+			name: "skips superseded review",
+			reviews: []gitea.Review{
+				makeReview(10, "bot", "APPROVED", false, "~~Original review~~\n\n**Superseded**\n<!-- review-bot:sonnet -->"),
+				makeReview(20, "bot", "APPROVED", false, "fresh review\n<!-- review-bot:sonnet -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantID:   20,
+		},
+		{
+			name: "only superseded reviews exist",
+			reviews: []gitea.Review{
+				makeReview(10, "bot", "APPROVED", false, "~~Original review~~\n\n<!-- review-bot:sonnet -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantNil:  true,
+		},
+		{
+			name: "picks highest ID among matches",
+			reviews: []gitea.Review{
+				makeReview(50, "bot", "APPROVED", false, "v1\n<!-- review-bot:sonnet -->"),
+				makeReview(30, "bot", "APPROVED", false, "v0\n<!-- review-bot:sonnet -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantID:   50,
+		},
 	}
 
 	for _, tc := range tests {