Only time I may lose aggro is during a long pull. I'll Unleash the first group, but the DPS continue to attack it while the mobs chase me. I'm not doing anything to these mobs since I'm busy running to the next group. If the distance is pretty far between groups, I can lose aggro to ranged DPS as they continue to attack. *MOST* DPS have enough sense to wait for every mob to gather on me after I pull all groups, before going all out.