  We reconsider QCD factorization for the leading power contribution to the
$\gamma^{\ast} \gamma \to \pi^0$ form factor $F_{\gamma^{\ast} \gamma \to
\pi^0} (Q^2)$ at one loop using the evanescent operator approach, and
demonstrate the equivalence of the resulting factorization formulae derived
with distinct prescriptions of $\gamma_5$ in dimensional regularization.
Applying the light-cone QCD sum rules (LCSRs) with photon distribution
amplitudes (DAs) we further compute the subleading power contribution to the
pion-photon form factor induced by the "hadronic" component of the real photon
at the next-to-leading-order in ${\cal O}(\alpha_s)$, with both naive
dimensional regularization and 't Hooft-Veltman schemes of $\gamma_5$.
Confronting our theoretical predictions of $F_{\gamma^{\ast} \gamma \to \pi^0}
(Q^2)$ with the experimental measurements from the BaBar and the Belle
Collaborations implies that a reasonable agreement can be achieved without
introducing an "exotic" end-point behaviour for the twist-2 pion DA.
