Sony A99 - My video test poses questions

If the problem that you talk about is the one that I am seeing, it's just the side effect of any optical wide angle lens made rectilinear. The implications are that moving in the center of the frame or at the sides is not done at the same speed. This is also why when shooting a still of a human face, it will appear very distorted when close to the edges of the frame. Try your video with a fish eye or longer lenses and the effect will disappear.