This paper presents a Tier-7 domain instantiation of the Paton Closed vs Distributed Recursion Law within thermodynamic phase transition analysis. It demonstrates that macroscopic phase stability corresponds to distributed recursive constraint sharing across microstate ensembles, while phase instability arises when recursive load localizes beyond admissible tolerance thresholds. The framework introduces no new physical laws and remains fully compatible with classical and statistical thermodynamics. Its contribution is structural: identifying recursive load localization as a cross-domain admissibility condition governing regime transition under constraint.