[Adam]

Here's why I think it doesn't happen more. A running start requires more precise timing; you need to know precisely when the shooter is going to release it. No way to do that. A "floating start" isn't so precise, as you can wait until the ball is released. You see a "floating start" occasionally. I remember Jordan did it a few times successfully.

Also, at the higher levels, the chances of the free throw being made go up, so the potential for reward is diminished. When you add the risks of a real violation, it becomes less "worth it" to try.

If they did it all the time, the opponents would adjust and make the tactic useless. Sorta like the flea flicker in football; it only works at that level if you only do it once every blue moon.

Bottom line; it's not a violation and it shouldn't be called unless you think either foot crossed the plane before the ball hits. Players off the lane have free movement within their very large area.

No, it's not disconcertion unless the shooter has eyes in the back of his head.