  We examine recent claims that evidence for an overtone in the ringdown of the
GW150914 binary black hole merger was a result of noise anomalies. We cannot
reproduce these claims, finding that our previous analysis of this event is
robust to data analysis choices and consistent with the expectation that strain
after the peak is well described as a superposition of quasinormal modes of the
remnant black hole. We discuss the meaning and implications of establishing
that any specific ringdown mode was detected, and argue that it is misguided to
expect actual LIGO-Virgo data to inform the discussion of whether or why the
merger looks linear.
