I think you are right. i was attacked by allies for the first time yesterday.  Bastard was tryign to steal my kill.  fighting the demons just above thell and noticed i was getting clocked from some mage, but luckly a respawn got him and deverted his attention so I could kill mine, heal and run...finishing the quest.  when I looked back he had 3 demons on him and i figured his Karma was ready for a reset.  

I did notice a lot of others fighting as I ran around.  I managed to avoid it, and luckly still unkilled by allies in BC so far.  i figure its just a matter of time till the unspoken truce of focusing on the quests gets to people and frustration of too few mobs for quests causes people to start ganking eachother to kill themobs v. taking 1 hour to kill 10 of this or 12 of that.