To reproduce on the OpenMRS demo site...
1.) Void a location tag.
2.) Edit an existing location, or add a new location.
3.) You will notice the retired tag is displayed.
4.) If you tick the retired tag and save the location, it will add that tag to the location.
When editing a location, the check box should not be able to be ticked for retired tags. When adding a location, it should probably not even show the retired tag.