  In a recent paper "Tests of general relativity with GW170817"
(arXiv:1811.00364 [gr-qc]) the authors claimed overwhelming evidence in favor
of tensor gravitational wave (GW) polarization over vector by analyzing GW
signals measured by the LIGO-Virgo network. Here we show that the measured
LIGO-Livingston signal is substantially reduced at certain frequency intervals
which can be attributed to noise filtering. We found that if these regions are
excluded from the analysis then data are consistent with vector GW polarization
and not with tensor. We show that if the signal accumulation method is applied
over the entire detector bandwidth, including the regions in which the signal
is depleted by noise subtraction, the result underestimates the LIGO-Livingston
signal amplitude. That smaller amplitude then leads to an erroneous conclusion
that favors tensor polarization over vector polarization for the GW.
