Of course
chi-sau doesn't have to be only passive, but the reaction of
lat sau jik chung is not simply an intentional strike when a gap is seen by the eyes, whether created by yourself or by the opponent's error.
That kind of fighting I would consider even more passive because you're relying on sight alone rather than feeling. So you're acting upon what you see. It's a slow and manual way of finding and striking targets.
That's why blindfolded
chi-sau is thought of as being mystical by you lot, because you have no use for sensitivity or concept of
lat sau jik chung. (There's apparently two of you playing on the same team, and neither can explain the concept.) That is also why the
chi-sau videos on your website show structureless slap fests, because it's two guys just trying to hit each other not caring what the other does.
http://www.wingchunkyn.com/videos/students-practices
http://www.wingchunkyn.com/videos/li-shou