we dont "rollback" the attributes of objects nor do we automatically expunge() them. its impossible for SA to "rollback" in-memory objects without great danger of stepping on other program state that the user doesn't want affected. the "rollback" that is performed by SessionTransaction is a "ROLLBACK" issued to all database connections that have been gathered up into the transaction, and thats it. any other clear()/expunge() operations are up to the user.