La. Stat. tit. 23 § 1632
Except insofar as reconsideration of any determination is had under the provisions of R.S. 23:1626, any right, fact, or matter in issue, directly passed upon or necessarily involved in a determination or redetermination which has become final, or in a decision on appeal under the subsection which has become final, shall be conclusive for all the purposes of this Chapter as between the administrator, the claimant, and all employing units who had notice of such determination, redetermination or decision. Subject to appeal proceedings and judicial review, any determination, redetermination or decision as to rights to benefits shall be conclusive for all the purposes of this Chapter and shall not be subject to collateral attack by any employing unit, irrespective of notice.
La. R.S. § 23:1632