  We showed in a recent article (Lawrence et. al., 2023, Quantum 7, 1015), that
relative facts (outcomes), a central concept in Relational Quantum Mechanics,
are inconsistent with Quantum Mechanics. We proved this by constructing a
Wigner-Friend type sequential measurement scenario on a
Greenberger-Horne-Zeilinger (GHZ) state of three qubits, and making the
following assumption: "if an interpretation of quantum theory introduces some
conceptualization of outcomes of a measurement, then probabilities of these
outcomes must follow the quantum predictions as given by the Born rule." Our
work has been criticized by Cavalcanti, Di Biagio, and Rovelli (CDR). In this
note we show that their critique is invalid, and that their specific arguments
raise questions of principle.
