This is quite common to see as the pilot moving the stick is simply causing an input to the flight control system to say what he wants the airplane to do. The computer then decides the best/most efficient/best performing way of achieving that input and will manipulate the surfaces (occasionally very quickly) to fill the "suggestion" if you will. You'll see the stabilators move on it and other fighters for roll usage as well.
Yep, I've seen stabilators doing that, but I haven't seen ailerons being used in that way before (providing more control modalities than normal airlerons or flaperons). It could be that F-16's, F-18's, and other fly-by-wire planes do the same but just that I never noticed it.
