When a question is assigned to more than one author, it's possible for multiple people to respond to a question simultaneously. This document explains how the concurrent edits works in Responsive.
When an author saves the response, the other authors working in the question/section will be notified after 20 seconds of saving the answer with a message as shown below:
To accept the edits made by the other author and override your response, select Accept Incoming Changes.
To ignore the edits made by the other author and continue with your response, select Ignore Changes. The other authors will be displayed with a notification icon. On mouse hovering it shows that the question has been modified by another author as shown below: