order gauge transformation, the behavior of the Zerilli function we obtain at the end of the process.

Does the appearance of a Zerilli function that does not vanish at infinity indicate something problematic in itself? We do not seem to see any difficulty in evolving the problem in this case. Our evolution code evolves a “slab” region consistent of the initial data and its domain of dependence, therefore we do not need to specify any boundary conditions. If one observes the behavior of the Zerilli function as a function of time for a fixed (finite) value of the radius, it starts having a constant value followed by a quasinormal ringing and a power law tail decrease towards zero. That is, the constant behavior at infinity translates itself in a certain behavior at the beginning of the waveform, it does not leave any visible effect after the ringdown and power law tail behavior. The radiated energy [*and all observable quantities at infinity*]{} (even to second order in perturbation theory, see section III.B of [@physrep]) are not determined by the Zerilli function itself but by its time derivative, for which the initial data indeed goes to zero for large values of the 