  By generalizing the well known results for reflection and refraction of plane
waves at the vacuum-medium interface to Gaussian light beams, we obtain
analytic formulas for reflection and refraction of the TM and TE laser light
pulses. This enables us to give a possible explanation why no reflection was
observed in light pulse photographs in some vicinity of the air-resin
interface, given in L. Gao, J. Liang, C. Li, and L. V. Wang, Nature 516 (2014)
74-77. We suggest how to modify the experimental setup so as to observe the
reflected pulse.
