Approved: All invited reviewers have approved the code review
Rejected: One or more reviewers rejected the code review
Pending: One or more of the reviewers have not set a review state and there are no rejected reviews

When an admin sets the review override on a revision, it will have one of the following statuses:

Approved*: The review override was set to approved by an admin
Rejected*: The review override was set to rejected by an admin

Any status overridden manually by the admin is indicated by an asterisk. The overall review status does not affect the review statuses set by invited reviewers and they are still able to change their review states.

Cleaning up a single stalled review

You can override the review state of a revision (or clear it altogether) by:

Logging into Code Review as admin, if you haven't already done so.
From your feed, you see the list of revisions. Find the revision you want to override (or clear) and from the drop-down menu, select the status that you want to set the revision to.
The revision details now display the overall state as set by the admin.

Cleaning up multiple stalled reviews using the Code Review Web API

If you need to clean up multiple stalled revisions or would prefer to script the process, you can use the Code Review Web API review_override action. For more information, see the Klocwork Code Review Web API cookbook.