  We discuss scattering from pairs of isospectral quantum graphs constructed
using the method described in [1, 2]. It was shown in [3] that scattering
matrices of such graphs have the same spectrum and polar structure, provided
that infinite leads are attached in a way which preserves the symmetry of
isospectral construction. In the current paper we compare this result with the
conjecture put forward by Okada et al. [4] that the pole distribution of
scattering matrices in the exterior of isospectral domains in R^2 are
different.
