Walking Goliath Essence creature had no drops.

Found a Walking Goliath trapped in essence. (Valley of the Titan, playthrough 1)

When I broke the essence all the goliaths were laying on the ground in pieces as if already dead. They got up after a little bit (may have been revived by a nearby necromancy skeleton?) and I killed them, rare included, but they dropped no loot or essences.
The rare was definitely affected by an essence, it had the essence modifier text and was generating large delayed impact zones until killed.

(edit: oops that was supposed to go to bug reports)