  In arXiv:1406.0957v1 ("Scalar field excited around a rapidly rotating black
hole in Chern-Simons modified gravity"), Konno and Takahashi have recently
developed some analytical results for the scalar field about a Kerr black hole
in the decoupling limit of dynamical Chern-Simons gravity. This involved a
decomposition of the source (the Pontryagin density) in terms of Legendre
polynomials. Here we give a two-line expression for this decomposition which
simplifies their quadruple sum. Our expressions are rational polynomials
multiplying Legendre functions of the second kind, or equivalently rational
polynomials multiplying hypergeometric functions.
