If you use Feint (rogue ability) or command your succubus (as a warlock) to use Soothing Kiss, it will normally cause whoever you're dueling to auto run randomly, causing them to be summoned, use a portal somehow or Alt-F4.
I'm guessing what causes this is aggro reducing abilities.
Only works in duels vs. your faction, not the opposing faction.
Works on WoWFusion, WoWScape and Toxic WoW for me.
Note - It won't always show them autorunning, they'll just appear frozen or something. (Usually I know when it works because people /y or whisper me angrily)