Index: mod/lesson/pagetypes/truefalse.php
===================================================================
--- mod/lesson/pagetypes/truefalse.php	(revision 17556)
+++ mod/lesson/pagetypes/truefalse.php	(working copy)
@@ -95,7 +95,7 @@
         }
         $result->newpageid = $answer->jumpto;
         $result->response  = format_text($answer->response, $answer->responseformat, $formattextdefoptions);
-        $result->studentanswer = $result->userresponse = $result->response;
+        $result->studentanswer = $result->userresponse = $answer->answer;
         return $result;
     }