This actually came up in a game of mine.
There were two dueling heroes each with one hit point remaining. Both heroes drew an orb. The defender's hero had no magic items. The attacker's had the spirit stealer (taker) which says to deal two damage with an orb and if it kills the enemy hero to heal the spirit stealer's hero fully. At the time, it was decided that combat is simultaneous and both orbs would resolve simultaneously and both heroes would die.
Now that Corey ruled that the attacking orb is resolved before the defending orb in battles, can this be extended to the hero duel that I had? Would this actually make the attacker's spirit stealer werapon go off first, killing the enemy hero and healing the attacker fully? I would assume that the defender's orb would be then resolved, dealing one damage to the now max life attacking hero (since unlike the berserker instance there are no invalidated criteria to the damage).