What he is doing is similiar to the peek-a-boo defense found in boxing.
Regarding traditional stances, I train them for conditioning and transitioning. Horse stance, bow and lunge stance, iron horse, leopard, ect. ect. are mostly not stances to fight out of, but more for transition. Conditioning was another main reason for low deep stances as is the Southern Kung Fu flavor.
Fighting out of these is not too smart, although I have seen some guys pull it off to an extent. Something has to constantly change and evolve to be perficient and fighting is no different. Like Ronin said, the element of suprise can be a good weapon.
"The hero and the coward both feel the same thing, but the hero projects his fear onto his opponent while the coward runs. 'Fear'. It's the same thing, but it's what you do with it that matters". -Cus D'Amato