[rules-users] [droolsflow] Constraint Editor

I have a flow that user (Human Task) can choose two ways: Valid Ticket and Invalid Ticket To pass to valid way, i used a MinataskClient.Complete and it works. But to go to invalid way, i try to used MinaTaskClient.fail, but this command not continue my task. My question is: 1) Whats the bast way to invalidade a ticket and finish the flow? 2) Its possible to get the task inside Split Constaint? (I think in this possibility. I get the task and check if it status=='FAILED') Thanks