Observation of shadow map in God Of War3

Today I have played a little bit of God Of War 3.

I know there was a presentation on GDC 2010 about shadow in God Of War3, but I cannot get it. Therefore I had to guess by looking at the result.

From by observation, it is definitely doing multi-sampling on a shadow map. Probably it does percentage closer sampling, because the penumbra reason is almost one pixel distance on shadow map. It is more clearly noticeable when the shadow is drawn on a edge.
I saw the shadow is often jumping. It gives me the impression that the shadow map is dynamically moving. It may moved to find the best angle between shadow map and the shadow receiver. It is also possible the position of shadow map is predefined by artists. This way reminded me of the shadow implementation of Halo series.

The character has only one shadow even when there are many lights around him.
Black shadow like texture appears when the character is under a shadow, which is similar result with assassin creed 2.

The game also uses static shadows from static objects with the dynamic shadows from characters. They get along well. When a character is inside of the static shadow, the dynamic shadow merges and disappear naturally.

I want to know how actually it works....