When a teacher or editor views Questionnaire results by response, the 'Print this response' link gives a 'no permissions' error. This is because /mod/questionnaire/print.php throws this error when user_can_take() returns false. Teachers/editors cannot take Questionnaires by default, so they always get the error.

The purpose of this condition is to prevent a 'snooper' from gaining access to Questionnaire results by typing the appropriate URL, but given that they can get access to the "view by reponse" page anyway using the same trick, there seems little point in preventing it here.