For example in the aurum vale, 1st boss casts on everyone (AoE) debuff which deal dmg per time, this dmg-type is considered single-target which deals full dmg to pet's (arcanist) instead of reduced, making anti-AoE mechanism of pets go in vain and flawing the game. Same goes for pools of poison or any other indirect AoE.
Seen this bug in every game that have summons and anti-aoe mechanism gotta see how/if SQEX react.