Should being Unflagged for PVP make you immune to other faction damage?

I started an alt on SOM. Was questing in Tirisfal and decided to run soul of iron to see how far i could make it. As i was fighting the scarlet (lvl 10) mobs down around the bottom right of the map,a ?? mage runs up to me casts frost nova and then cone of cold on and now im dead. Im not flagged yet he was able to do AOE damage and kill me in my own zone.Do you guys think being unflagged should make you immune to opposite faction AOE damage in the future seasons? Discuss belowEdit: i should have specified AOE Damage in the title because that seems to get through the being unflagged.