I will correct an earlier mistake on our part - there was no mobile IP shared between the nations. We will never normally comment on this kind of information, and it was a mistake for it to have been said in the first place (even putting aside the inaccuracy of it); nonetheless, as it was said and it was wrong, I feel it is appropriate to correct this.
Discussions on our ways of detecting multies inevitably turns into a discussion of how to get away with multying, even if that is not the intent of participants. That is not a discussion we are going to allow. I will never claim our methods are foolproof; we have no direct contact with the people playing the game; however, they are much more sophisticated that people imagine, and we've caught many a cheater who has thought using different devices would help them evade our checks.
As for G-R's suggestion that "TEP is lying, or that Mods are wrong", I don't believe that to be the case. TEP has a different set of evidence to us, and has chosen to interpret what they have differently to how we've interpreted our evidence.
As a final point, made in general rather than on this specific case, I'll note that consistent IP matches between two nations do not necessarily indicate that they are the same person. An example being Sedgistan and Crazy Girl.