Interesting post over on the Tyner Blain blog Use Case vs. UML Statechart - Business Rules. This post does a good job of differentiating between use cases and UML statecharts with a view to finding the business rules. Of course, it goes without saying that I think the business rules should be managed as first-class objects in some kind of rule repository, even at the requirements gathering stage, not embedded in the notes attached to either diagram (the post does not make their position clear on this).
