I'm using SWF 2.0M3 with persistence context configured for Hibernate.
When commiting the changes I got an org.hibernate.StaleObjectStateException as expected, because I modified the same object in two separate flows.
The first problem is, that this exception is absorbed in the exception wrapping code for an inactive flow in FlowExecutionImpl.
The second problem is, that the HibernateFlowExecutionListener tries to unbind the session from an inactive flow in exceptionThrown(), which causes a new exception.
In the end the hibernate session is still bound.