FRCP, Administrative Law, Deference
(Complex. Here's an especially guesslike guess.)
Where a statute implements a treaty but is not the sole implementation of a treaty, a court's subsequent shift in the basis for the decision does not violate the law of the case, as there are potentially several statutes at issue.
Where more than one statute enables a rulemaking, deference can be shown to an agency's interpretation of one regulation despite law of the case to the contrary with respect to the other statute.
The differences in the means of practical implementation can make contradictory agency decisions in substantially similar cases not arbitrary/capricious.
Dissent - The second statute doesn't independently implement the treaty, so there's no deference to agency on substantive matter of interpretation - the second statute is merely procedural. No Skidmore deference on present agency interpretations, as it's not persuasive. Procedural differences don't justify different handling of identical cases.
http://www.cafc.uscourts.gov/sites/default/files/opinions-orders/14-1581.Opinion.1-4-2016.1.PDF
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.