Originally Posted by LuckyR
Actually the OP is confusing two separate issues.
First, the particular individuals involved in this particular match like to "wish" the ball out and are perhaps cheaters. Perhaps Cindy is getting so much topspin on the ball that the inflight trajectory looks out in midair and dives down at the last second to touch the line.
As to the geometry of line calling, the netman actually has an unobstructed view of court between the ball and the line. The baseline player's view of this is often blocked by the ball itself. Not to mention that the baseline player is trying to actually hit the ball and that the ball is moving across their field of vision rapidly, neither are a problem for the netman looking back.
It's harder to call a ball at the baseline if the ball is moving and is near your feet. The net person has a better view in a lot of instances.