Sometimes, while in a party, I open a chest or I kill a monster and all the loot is flagged with one of my friend's name. Why ?
You can check here how it got to the current FFA looting.
In the first page, you can see the official response:
When an item drops, how do you decide who gets the temporary allocation? Randomly among nearby players.
By the way, it's still an open beta, so it may change with any patch.