Use Groovy to automatically assign user (contract administrator' when completing contract review

Summary:

I have found this post https://community.oracle.com/customerconnect/discussion/548627/assign-user-status-code-pending-signature

I have a similar requirement to support below business flow

1. Contract administrator assigns contract to user to conduct for instance a 'legal review' --> in place and working as designed

2. Legal completes the review. --> currently they select user status 'review completed' and now have to manually re-assign the contract back to the contract administrator.

Content (please ensure you mask any confidential information):

Is there any way I could use a groovy script to make sure the action 'assign user' will not be manually invoked but automatically reassigns the contract to the contract admin?