failure with diverged branch when doing a release

I was in the middle of a release when I got the following error:

These branches have diverged. Try using "merge" and then "push".
 * ERROR: Some error occurred!
 * Cleaning up....

I verified that the branch really had diverged by checking the revno. After checking with my coworkers this is what happened:

1) Coworker started a release (created the branch that mirrored the target server)
but did not respond Yes to the release.
2) I started a release (worked on composing a commit message)
3) Coworker completed his release.
4) I tried to complete the release and got the message that the
branches had diverged.

It would be helpful to catch the branch divergence message and at a minimum tell the user to try the release again instead of merge and then push. Better might be to notify that the branch had changed during the release, do another pull overwrite of the target server mirror branch and then remerge.