Proposition: Exact event-time calibration is deterministic

At one fixed event and with distinct $t_k$, exact event-time calibration permits at most one supported outcome. If no $t_k=T(e)$, no normalized exactly calibrated input exists.

Proof. At most one code has the required coordinate. Normalization forces its probability to be one. For a state $\rho$ and the complementary projector $Q$,

forces support in that single clock subspace.