PvP and Priests

A level 25 Assassin challenged me to a duel, and I thought to myself, why not. I was a level 16 Priest. In the 10 second preparation countdown prior to the duel, I buffed myself. But instead, I had targeted my opponent and was actually buffing him. When the duel started he went invisible or something and then attacked me and started eating away at my HP. I used Heal and Healing Touch while targeting him. In PvP, would it heal me or him?

In Player Vs Monster, it heals me.