diff --git a/CODESMELL.md b/CODESMELL.md
index a9a7296..ccc703c 100644
--- a/CODESMELL.md
+++ b/CODESMELL.md
@@ -414,9 +414,11 @@
 
 ---
 
-### CSM-027 — `if result == :ok` Instead of Pattern Matching
-- **File:** `lib/bds/templates.ex:445`
-- **Fix:** Use `case result do :ok -> ...; _ -> ... end`.
+### ~~CSM-027 — `if result == :ok` Instead of Pattern Matching~~ ✅ FIXED
+- **Fixed:** 2026-05-11
+- **What was done:**
+  - Replaced `if result == :ok and ...` in `rewrite_template_file/2` with a `case` expression using pattern matching and a `when` guard.
+  - `Persistence.atomic_write` result is now matched directly: `:ok when file_path changed` triggers old file cleanup, `other` (including `{:error, _}`) is returned as-is.
 
 ---
 
diff --git a/lib/bds/templates.ex b/lib/bds/templates.ex
index a15e0a1..790622c 100644
--- a/lib/bds/templates.ex
+++ b/lib/bds/templates.ex
@@ -448,13 +448,12 @@ defmodule BDS.Templates do
     body = published_template_body(original_template)
     new_full_path = full_file_path(updated_template.project_id, updated_template.file_path)
 
-    result =
-      Persistence.atomic_write(new_full_path, serialize_template_file(updated_template, body))
+    case Persistence.atomic_write(new_full_path, serialize_template_file(updated_template, body)) do
+      :ok when original_template.file_path != updated_template.file_path ->
+        delete_file_if_present(original_template.project_id, original_template.file_path)
 
-    if result == :ok and original_template.file_path != updated_template.file_path do
-      delete_file_if_present(original_template.project_id, original_template.file_path)
-    else
-      result
+      other ->
+        other
     end
   end