Some of the skills this kind of problem:
Dust Blast, Battle Stomp
Samples of the battles that I have encounter this problem.
1) In Arx, when I fight Nemesis (enemies) and those Paladin are neutral.http://steamcommunity.com/sharedfiles/filedetails/?id=1350970260
2) Just outside the city of Arx, when the Paladin is attacked by Vampiric Void.
3) Saving Sahelia, when Saheila is neutral.http://steamcommunity.com/sharedfiles/filedetails/?id=1350970212
Please kindly stop let the above skills attacking neutral NPC, it is not intended.
If the neutal NPC joined the battle, I can not use Dust Blast.
Otherwise the NPC will become hostile.
Edit 1: added screenshot.
Edit 2: If you check the description of Dust Blast and Pyroclastic Eruption, both state that it would target enemies. Currently, Dust Blast also target neutral NPC but Pyroclastic Eruption would not.