Better explanation of implicit exception response status code

Author: hvt

reference/events.rst

@@ -215,10 +215,12 @@ and set a new ``Exception`` object, or do nothing::
     response won't work. If you want to overwrite the status code (which you
     should not without a good reason), set the ``X-Status-Code`` header::
 
-        $response = Response(
+        $response = new Response(
             'Error',
-            404 // ignored,
-            array('X-Status-Code' => 200)
+            404, // this status code will be ignored
+            array(
+                'X-Status-Code' => 200 // this status code will actually be sent to the client
+            )
         );
 
 .. seealso::