All people have to roll for item to finish the roll. We had weird situation when doing random LFG
Me - greed
Mage - greed
Shaman - need
Shaman won: Trinket
People was confused because only 3 people roll for this and rolling just finished, instant won item. 2 persons even didn't had chance to press need, how it's possible?
Only those who participated in kill from very start till end, and stayed in zone, are eligible for loot rolling.
Those two guys either left dungeon zone or weren't there at start of encounter.
Of course there is chance that they are just VERY slow and just wasted their time period to roll dice for the item.