I'm surprised the judge issued a warrant for this, in light of the Constitutional issues involved here -- but unfortunately I'm not aware of any way to sanction a judge for doing so; the only remedy for a defective warrant is suppression of evidence obtained from it.
Unfortunately, Constitutional protections are only a defense to libel, so the prima facie case can still be made, and the warrant could technically still issue.
The elements of criminal libel in Louisiana are clearly enumerated at http://law.justia.com/codes/louisiana/2006/146/78544.html. If the written article constitutes facts sufficient to allege a violation, then a warrant can issue.
Unfortunately, Constitutional protections are only a defense to libel, so the prima facie case can still be made, and the warrant could technically still issue.
Sigh. The law sucks sometimes.