As with an attack, the decoy is gone and she got a wound for her trouble.The target turns out to be a psychic decoy, which harms you as you attack it.
However, given Blood Heal isn't really an attack, I'm not sure if that was supposed to happen?
ETA:
Past Reports on Decoys
Decoy Blowing up without being attacked
Decoy blowing up from an inspire (in same square)