I have actually had Casa ( DCA maybe DOT ) review an engineering exam wayback and i didnt ask for it , they came up with a pass for several of us , apparently someone requested it because we did so bad , they had mixed up the marking sheets . I have requested a remark for some flying exams and was given the same reply as you . Back to the books i,m afraid their is several correct answer but only one really correct .Remember there is always light at the end of the tunnel but first you have to find the tunnel . Good Luck