Is there any way of set a Nintex Flexi task completion through Sharepoint's web services? We have tried updating the "WorkflowOutcome", "ApproverComments" and "Status" fields without success (actually the comments and status are successfully updated, however I can find no way of updating the WorkflowOutcome system field).
I can't use the Nintex Web service (ProcessTaskResponse) because it needs the task's assigned user's credentials (login, password, domain).
The Asp.net page doesn't have that information, it has only the Sharepoint Administrator credentials. One way is to delegate the task to the admin first, and then call ProcessTaskResponse, but it isn't efficient and is prone to errors.
In my tests so far, any update (UpdateListItems) to the WorkflowOutcome field automatically set the Status field to "Completed" and the PercentComplete field to "1" (100%), ending the task (and continuing the flow), but with the wrong answer: always "Reject", no matter what I try to set it to.