Hey, unfortunately this trainer seems to bug out any random duel encounter like someone mentioned it already. Its a realy weird bug where the second npc who gets shot in the duel will be revived as soon as he hits the ground and suddenly both npcs shot at you no matter where u are. Its even worse in Van Horn because the whole city is attacking you.
I found this video on reddit and it seems to be the same bug. Its realy annoying and i hope u can fix it in the future. For the time i try my best to avoid these encounters.
I removed all mods but this trainer. The bug is related to version.dll