DIR 11 needs to be filed 1st and then DIR 12 should be filed.
It is duty of Director to file DIR 11 by himself with his own DSC within 30 days of his resignation. No penalty prescribed (other than filing fee penalty) however facility of DIR 11 was introduced as there were complains of frauds in Form 32 of earlier act. DIR 11 safeguards the resigning director for any such frauds.
If you file 1st - DIR 12 and 2nd DIR 11, then DIR 11 wont be filed as name of that particular director shall be removed from the servers of MCA as and when you filed DIR 12 because it is STP Form. Once a director has filed DIR 11, he can not be held liable for things or acts done by Company by taking in his name. DIR 11 with challan if shown in Court of Law is acceptable as proof of proper regisnation by a director. A resigning director in no case concerned with filing or not filing of Form DIR 12 by the Company.