  In a recent preprint, hep-ph/0012253, Zhu et al. calculated a part of the
next-to-leading order corrections to parity-violating pion photoproduction
(pol)gamma p-> pi^+ n in heavy-baryon chiral perturbation theory. They claim
they have found the contribution as large as the leading-order. If correct, the
process will not be a clean way to extract the longest range PV pion-nucleon
coupling constant h_{\pi NN}^(1), as was asserted in our previous publications
(hep-ph/0011230, nucl-th/0011100). In this comment we show that there is no
solid evidence to support Zhu et al.'s claim. Moreover, we show that the
subleading parity-violating coupling h_V cannot be extracted from observables
at the order of interest based on the formalism of effective field theory.
