In another video he talks about "chase the center, don't chase hands", yet this is his strategy:
http://www.youtube.com/watch?v=hnRZzuQAmG8
He shifts to move out of the way and block. This is being afraid of the hands and chasing them to the side trying not to get hit.
In contrast, gaang-sau as we do it must be directed at the opponent's mass, not to the side at their arms. The jam-sau arm "cuts the way" down the center to hit the opponent in one beat. That's "chasing the center". Kwan-sau must also be driven to affect their core, not bat their arms.
But here, he turns and blocks with his hands going sideways away from the opponent, "chasing the hands". He will need another step to attack, but by then he'll have to chase the other hand. Yet he talks about "don't chase hands" in another clip, not realizing that his whole approach is exactly that!
So sure, given a strategy like this, the baiting guard is going to be useless because you're still chasing hands. Our target is always the person, not their arms. Narrowing their lines of attack to mainly one side means we need care even less about their arms and carry on hitting them.