  We inspect the first-order electron-electron capture scenario for transfer
ionization that has been recently formulated by Voitkiv et al. (Phys. Rev. A
86, 012709 (2012) and references therein). Using the multichannel scattering
theory for many-body systems with Coulomb interactions, we show that this
scenario is just a part of the well-studied Oppenheimer-Brinkmann-Kramers
approximation. Accurate numerical calculations in this approximation for the
proton-helium transfer ionization reaction exhibit no appreciable manifestation
of the claimed mechanism.
