It happens every once in awhile at the federal level when the solicitor general, on behalf of the U. S. , will confess error or decline to defend a law. I don't know what is going through the [Obama] administration's thought process on 'don't ask, don't tell. ' It would be appropriate for them to say 'the law has been deemed unconstitutional, we are not going to seek further review of that. '
Everything is useful which contributes to fix the principles and practices of virtue.