Systems may satisfy admissibility, execute correctly, and retain structural return paths, yet still lack a structurally fixed point at which consequence becomes binding. This note isolates that missing condition. The boundary is not execution, nor the disappearance of return, but the point at which carried-forward state can no longer be made causally irrelevant across admissible futures. From that point onward, rollback becomes transformation, recovery carries consequence, and prior-state operation is no longer valid.
Skulski et al. (Thu,) studied this question.