  In arxiv: 2102.05575 a two-step process $pn \to (pp) \pi^- \to (\Delta N)
\pi^- \to (d \pi^+) \pi^-$ was calculated by using experimental total cross
sections for the single-pion production processes $pn \to pp \pi^-(I=0)$ and
$pp \to d \pi^+$. As a result the authors obtain a resonance-like structure for
the total $pn \to d\pi^+\pi^-$ cross section of about the right size and width
of the observed $d^*(2380)$ peak at an energy about 40 MeV below the
$d^*(2380)$ mass. We object both the results of the sequential process
calculation and its presentation as an alternative to the dibaryon
interpretation.
