  Sznajd-Weron in [Phys. Rev. E {\bf 82}, 031120 (2010)] suggested that the
one-dimensional Ising model subject to the zero temperature synchronous Glauber
dynamics exhibits a discontinuous phase transition. We show here instead that
the phase transition is of a continuous nature and identify critical exponents:
$\beta \approx 0$, $\nu \approx 1$, and $z \approx 2$, via a systematic
finite-size scaling analysis.
