Suppose client A invokes a method on a stateless session bean. While waiting for the method to complete, client A passes the component interface to client B. Client B invokes a method on the given component interface while client A is still waiting for the method to be complete. Client B will get an exception.
With stateless it might happen if the conatiner cannot convert concurrent calls into sequential pocessing by the bean when there is only say 1 bean in the pool and there is no provision to increase the bean size or make new beans
The container must enforce this policy;therefore, I don't think this scenerio will occur.