  In a recent Letter, it was suggested that a previously neglected Standard
Model process, namely, the production of antihelium-3 nuclei through decays of
$\bar\Lambda_b$ baryons can lead to a flux of antihelium-3 from dark matter
annihilations detectable by AMS-02. We show that an essential condition for its
detectability -- the introduction of the "$\bar\Lambda_b$ tune" of Pythia -- is
excluded by a wealth of measurements of (anti-) baryon and (anti-) meson
production at accelerators. Moreover, we argue that Monte Carlo generators like
Pythia should not be used to predict branching ratios like $BR(\bar\Lambda_b\to
\bar u d u (ud_0))$, which control the formation rate of antihelium-3. In
particular, we show that $\bar\Lambda_b$ decays which proceed via diquark
formation are overestimated by Pythia using its standard settings, which are
further enhanced in the "$\bar\Lambda_b$ tune".
