It doesn't matter if where the player actually is, is somewhere else. As long as you aim at them and shoot before they shoot you, even if they are no longer the

It doesn't matter if where the player actually is, is somewhere else. As long as you aim at them and shoot before they shoot you, even if they are no longer there, the server will "rewind" and say you shot them, up to a certain limit. This is covered in your link :)