When a task is assigned with Team Filter Services a temporary team is created and the task assigned to that filtered temp team.
It is possible that a user claims the task and when he completed the action e.g. approve the user is no longer a member of the authorized filtered team
One way to handle this is pass in the inputs to the Team Filter to the task and the task will rerun the teamfilter with the same inputs as the task and determine if the user is currently a member of the filtered team. You can reassign the task back to the newly generated team if the user is no longer a member after displaying an appropriate message.