Enemies not getting destroyed with the axe mastery

So I have the "enemies you hit are destroyed on kill" axe mastery passive, but I noticed with the porcupine mobs and the detonate nearby corpse strongboxes that not all enemies were getting destroyed. The only reason I could think of is that the ancestral call visages don't count as being hit by me for the purposes of this mastery passive. Would this be right or is this a bug?