Naturally I read the document but I can say that it is not behaving like it is there described, at least not with jbpm console
'11.7. Swimlane in start task
A swimlane can be associated with the start task to capture the process initiator.
A task can be specified in a start-state. That task be associated with a swimlane. When a new task instance is created for such a task, the current authenticated actor will be captured with Authentication.getAuthenticatedActorId() and that actor will be stored in the swimlane of the start task.'
That is definitely not happening, the group that I defined for the swimming lane is assigned to the task as ActorPool but Task is not assigned to the actually authenticated user, I have to do that manually....
To make the thing worse, I can assign an actor that is not belonging to the group defined in the swimlane and jbpm doesn't complain about that also....
yeah that's the behaviour for jBPM3, if you are using jBPM4 it's a different story, the user starting the process is stored in the history, see this thread: http://community.jboss.org/thread/154420
furthermore as far as i understand the concept of a swimlane: its job is to provide a kind of "process role" in order to assign the same user(s) to a number of tasks, being able to override the assigned user, like you describe, is not a problem in my opinion, it is a valid business case in my opinion and your application code should handle this and decide if this can be done or not.