in mr vunaks defence before he checks he has already defanged the snaked by cutting the knife hand/arm of his attacker, the checking pretectects his body from the follow through of his attacker. at middle range if paul had missed the defanging move, then his opponents knife would have carried on to a vital target like the neck or torso/heart.

he covered why he uses the check at middle range as opposed to "long arm range" and how the arm is used differently at close range. that might clear some of it up, i thought the whole video was gold and im considering getting the dvd's.
its not supposed to make sense