Hmmmm I went back in and it wasn't the sword at the same spot, it was a purple necklace instead.Loot drops don't change if you yield or die, you can go back and get it again. That's what I did yesterday - I wiped on the bosses I tried, but on the way to each I got a red T5 ring. So I went back in, collected the rings from the mobs that dropped them, and peaced out via the portal.
This is the new raid thing.