Currently, when syncing RP to RE, Contributions to Other Organizations merely exports the data and imports it into RE. It does not check whether or not contributions in RP have been deleted or rejected and remove those from the RE record. The result is that RE data may not end up matching the RP data since the sync process can only add or change information in RE but not remove data appropriately. That it's called "sync" feels misleading since the process doesn't actually synchronize the two databases.