  Using a cleanly tagged data sample of $\nu_\mu$ charged current events, it is
demonstrated that the rate at which such events are mis-identified as $\nu_e$'s
is accurately simulated in the MiniBooNE $\nu_\mu \to \nu_e$ analysis. Such
mis-identification, which could arise from muon internal bremsstrahlung, is
decisively ruled out as a source of the low energy electron-like events
reported in the MiniBooNE search for $\nu_\mu \to \nu_e$ oscillations. This
refutes the conclusions of a recent paper which postulates that hard
bremsstrahlung could form a substantial background to the MiniBooNE $\nu_e$
sample.
