  The concept of group velocity of a particle should be consistent with its
Hamilton-Jacobi velocity. This point is missed in the work of Cohen, Glashow,
"{\it Pair Creation Constrains Superluminal Neutrino Propagation}" (Phys. Rev.
Lett. {\bf 107}, 181803 (2011)). It then leads to the conclusion of existence
of Cherenkov-like radiation provided one sees superluminal neutrinos. We show
that in the framework of Special Relativity with de Sitter space-time symmetry
(dS-SR) the above Cohen-Glashow argument does not hold and the Cherenkov-like
radiation is forbidden. Our result is consistent with the experimental results
of the ICARUS Collaboration.
