WTF? Unable to revive neutral hostile heros?!

I have this perplexing problem in a map where I cannot revive heros belonging to neutral hostile using the "hero - revive" trigger.
It's nothing to do with the triggers, I can delete the triggers and create a new revive trigger and it wont work, or I can move the triggers to another map, and the creep heros will revive when I run the trigger. Gah.

I can change the owner of the deceased hero, then revive it. So I can use this is a workaround.

But does anyone have any idea why the revive action wouldn't work for Neutral Hostile?!

In the unit customs there is a thing that says type. Change it from Creep to what ever you want the unit be be elf, orc, commoner and so on...;)

Typically heroes cannot be creeps, only player controlled so blizzard may have overlooked that possibility when they made the editor, UMSWE may have fixed it, but I suspect they probably overlooked it too.