"HW rulez" mod (add-on) for HoMM3.

Hey guys, can anyone help me out? Yesterday, during a tournament game against Amster, a strange situation occurred. We were playing with one-way portals. Throughout the game, the one-way portals worked as expected, connecting the entrance to the entrance and the exit to the exit. However, at one point, when my opponent's main unit was standing in one of the exits, my unit passed through the entrance, and an unexpected battle occurred, which could indirectly affect the outcome of the game. My question is: is this a bug, or is it supposed to happen? And what should we do next? I made a save immediately after the contact.