  Takahashi & Soda (2010 Class. Quantum Grav. v27 p175008, arXiv:1005.0286)
have recently considered the effect (at lowest non-trivial order) of dynamical,
quantized gravitational fluctuations on the spectrum of scalar Hawking
radiation from a collapsing Schwarzschild black hole. However, due to an
unfortunate choice of gauge, the dominant (even divergent) contribution to the
coefficient of the spectrum correction that they identify is a pure gauge
artifact. I summarize the logic of their calculation, comment on the
divergences encountered in its course and comment on how they could be
eliminated, and thus the calculation be completed.
