First, you will have to post the California decision. Secondly, what rules of war are we talking about? Spying has nothing to do with this. Finally, since when did any Court say that an American can be held without due process on US Soil by the US Military that has not been charged with handling Americans in the first place?
The detention is totally Unconstitutional.
The Supreme Court explained all this in 1942.
The Court in California dismissed the case for lack of Jurisdiction. It was appealed but the appeal court has not ruled yet.
I guess we will see who is right when it gets back to the Supreme Court to rule on the same issues. The last time it was 8 - 0.