  The manuscript by Berezhiani (arXiv:1812.11089) proposes a model that has the
neutron decaying into a mirror neutron with a branching fraction of 1%,
alleviating the tension between neutron lifetime measurements in beam vs bottle
experiments. We show that the model as proposed is inconsistent with
experiment. Variations of the model may work at the expense of extreme breaking
of the $Z_2$ symmetry between the Standard Model and its mirror copy.
