  Results presented in a recent paper "Which is the Quantum Decay Law of
Relativistic particles?", arXiv: 1412.3346v2 [quant--ph]], are analyzed. We
show that approximations used therein to derive the main final formula for the
survival probability of finding a moving unstable particle to be undecayed at
time $t$ force this particle to almost stop moving, that is that, in fact, the
derived formula is approximately valid only for $\gamma \cong 1$, where $\gamma
= 1/\sqrt{1-\beta^{2}}$ and $\beta = v/c$, or in other words, for the velocity
$v \simeq 0$.
