  Inner-shell vacancy production for the O$^{8+}$-Li collision system at 1.5
MeV/amu is studied theoretically. The theory combines single-electron
amplitudes for each electron in the system to extract multielectron information
about the collision process. Doubly-differential cross sections obtained in
this way are then compared with the recent experimental data by LaForge et al.
[J. Phys. B 46, 031001 (2013)] yielding good resemblance, especially for low
outgoing electron energy. A careful analysis of the processes that contribute
to inner-shell vacancy production shows that the improvement of the results as
compared to single-active-electron calculations can be attributed to the
leading role of two-electron excitation-ionization processes.
