  Background: One-neutron removal reactions are used to study the
single-particle structure of unstable nuclei, and in particular the exotic halo
nuclei. The Eikonal Reaction Theory (ERT) has been developed by Yahiro, Ogata
and Minomo in Prog. Theor. Phys. 126, 167 (2011) to include dynamical effects,
which are missing in the usual eikonal description of these reactions.
Encouraging results have been obtained for total breakup cross sections in
comparison to more elaborate reaction models.
  Purpose: We extend these comparisons to more differential breakup cross
sections expressed as functions of the relative energy or parallel momentum
between the core and halo neutron.
  Method: ERT predictions of these cross sections are compared to
state-of-the-art calculations.
  Results: The hypotheses upon which the ERT is based are confirmed and their
range of validity is made clearer. The actual ordering of the evolution
operators {affects ERT differential} cross sections and a specific choice leads
to excellent agreement with the reference calculation. Dynamical effects in the
treatment of the neutron-target interaction can be significant in the
parallel-momentum observable.
  Conclusions: The role of the different interactions in the dynamics of
breakup reactions of one-neutron halo nuclei are better understood and
improvements to the ERT are suggested.
