Deleting docker image leaves dangling image of same ID

When I have 2 images with different tags but delete one using curl, it removes the sha file and the latest image but leaves the other image there. This was intentional after NEXUS-12711 but further work could be done so delete both images.
The workaround is run the delete again and it will remove the second image.

Steps to repro:
1) docker pull hello-world
2) docker tag hello-world <hosted:port>/hello-world
3) docker push <hosted:port>/hello-world
4) docker tag hello-world <hosted:port>/hello-world:second
5) docker push <hosted:port>/hello-world:second
6) curl -v -u 'admin:admin123' -H 'Accept:application/vnd.docker.distribution.manifest.v2+json' https://<hosted:port>/v2/hello-world/manifests/latest -k
7) curl -v -X DELETE -u 'admin:admin123' https://<hosted:port>/v2/hello-world/manifests/sha256:<Docker-Content-Digest> -k
8) curl -u 'admin:admin123' https://<hosted:port>/v2/hello-world/tags/list -k
shows "second". UI also shows image and manifest for second.
WEIRD9) curl -v -u 'admin:admin123' -H 'Accept:application/vnd.docker.distribution.manifest.v2+json' https://<hosted:port>/v2/hello-world/manifests/second -k
shows the <Docker-Content-Digest> same as latest. So seems an associated file is now missing (on push, both the manifest and sha file are created).