  In a recent paper (Phys. Rev. D78, 084031 (2008), arXiv:0808.0642, Ref. [1])
it was shown in examples that the covariant retarded Green's functions in
particular gauges for electromagnetism and linearized gravity can be used to
reproduce field configurations correctly in spite of the spacelike nature of
past infinity in de Sitter spacetime. In this paper we extend the work of Ref.
[1] concerning the electromagnetic field and show that the covariant retarded
Green's function with an arbitrary value of the gauge parameter reproduces the
electromagnetic field from two opposite charges at antipodal points of de
Sitter spacetime.
