That difference in quality is not much at all, and you do not know what his orders were. However, several people have had their opponent's team (or theirs) get stronger when they go down to 10 men whether through injury or red card. No game is perfect, and i personally think that fluke results add a touch of reality to the game - it is not that hard to believe that a 10 man team could beat an 11 man team of slightly better quality in real life, although I have to admit, probably not by such a margin.