So with this new feature that lets you track down people who rob you I decided to chase down an enemy who had just robbed one of my carts. I caught up to him, clicked duel, and a battle started. He did the tactic of just fielding a single hero against my army, so it was an easy victory. Right after, I looked at my map, expecting to see him at his capitol (which was Skarn and I was in Neferak, so pretty far away) , but his icon showed up at a city a few seconds walk from where I was! I rushed over and low and behold, there he was attacking someone's Garrison!
At first I thought it might just be a visual bug introduced with the rob tracking feature, but I asked the house who owned the city that he had attacked if he had attacked them a few minutes ago, and they said he had indeed shown up in their history as attacking a garrison right about the time that he was supposed to be dueling me. Also, I know it was not a player with the same name because this player was an Inquisitor, so he had the Inquisitor tag beneath his name.