Wrong UUIDs accepted and reflected in db during cli cmd exectution

After a devstack install, playing with keystone cmds. For the sub-cmd user-role-add, by mistake I used the role UUID for both role and user UUIDs. The cmd executed successfully and values reflected in db (Tables: metadata and user_tenant membership)

deepak@deepak-devvm:~/devstack$ keystone role-list
+----------------------------------+----------------------+
| id | name |
+----------------------------------+----------------------+
| 3bc97204d7df40788c4bfa1b66ff3d14 | anotherrole |
| 597e1ab461df42d2847b02ae053112f7 | Member |
| 5ceef439c8ab4cfc8abee359ced4758c | admin |
| 650abec8e72645928ce2bfae1222b192 | KeystoneAdmin |
| b8cf5415a4d84791aa8c1049b4fc7c50 | KeystoneServiceAdmin |
+----------------------------------+----------------------+
deepak@deepak-devvm:~/devstack$ keystone user-role-add --user=3bc97204d7df40788c4bfa1b66ff3d14 --role=3bc97204d7df40788c4bfa1b66ff3d14 --tenant_id=6d7ccff941e843ee86340a3a964720b7

This is also true for user-role-remove subcmd.

Similarly trying to use tenant uuid for all the three options, I get the error: "'NoneType' object has no attribute 'iteritems'
"

deepak@deepak-devvm:~/devstack$ keystone tenant-list
+----------------------------------+--------------------+---------+
| id | name | enabled |
+----------------------------------+--------------------+---------+
| 36e434a5c60445a6a46cb7c0c779f26f | demo | True |
| 6d7ccff941e843ee86340a3a964720b7 | service | True |
| c3ceb42f641a4227bcef9719fde82d82 | admin | True |
| fb1fbc76098b4d9ea8fef457069a3175 | invisible_to_admin | True |
+----------------------------------+--------------------+---------+

deepak@deepak-devvm:~/devstack$ keystone user-role-add --user=6d7ccff941e843ee86340a3a964720b7 --role=6d7ccff941e843ee86340a3a964720b7 --tenant_id=6d7ccff941e843ee86340a3a964720b7
'NoneType' object has no attribute 'iteritems'