Moving Backwards in Incident to Categorization while having open task

Hello Everyone,

Need a guidance here. I have modified my incident workflow to have a button to move back to "Categorization" from Investigate phase(my requirement is like that). To do this i have done the below,
1. Created a transition from "Investigation" to "Categorization".
2 Created a ruleset to set the Status="Categorize" through javascript.

My requirement is fulfilled and it works fine as long as i have not open task. When there is a open task, it throws an error saying "The Incident will not leave the current phase until the following task closed" and display the task number.

Here i want to know how can this been rectified.

1. Is the only option left here for me is to close the task automatically when moving back to categorization phase? if so how can i do this. through a ruleset?
2. Or can we move the task also backward in phase level which does not bring the above stated error? I m not sure. just asking.

Thanks in advance.!