Database server administrators use the dbo schema, so data they create has dbo in the dataset name. Any user who is a member of dbo (in other words, any user who is a database server administrator) is considered owner of the datasets in the dbo schema. When you altered the geodatabase-wide permissions for editor1 and manager1 in the buildings geodatabase, those permissions applied to the datasets in that geodatabase. For example, editor1 was granted read/write geodatabase-wide permissions on the buildings geodatabase so has read/write access to all data in that geodatabase. You cannot alter editor1's dataset-level permissions for any data in this geodatabase because he or she.
