I noticed a funny thing. Even if it is working as intended I think, this is awesome. If you are a warrior priest, and want to not only leech EXP and INF on a PQ, but also get some decent loot, make sure to get in the group with 5 melee careers.
Then you only have to make sure to activate your ability Prayer of Devotion, and place your self somewhere in middle. I done that, and went afk. To my big surprise, I had 450+ to the roll among other 15 people in my group.
The only reason for it as I see it, that Prayer of Devotion (20% chance to heal party member when they hit NPC) healing is counted in your contribution. And when there are 5 people constantly meleeing mobs, PoD procs alot.
I am not 100% sure about this, but I dont see any other reasons for me having 500 adn 450 contribution while being afk
So pop PoD and enjoy your loot while afk.