Last night we had a level 45 join Kromede's Temple group we created.
They proceeded to drag Rotan up to the spot where you kill the mini boss, jump across and get the Temple Kisk, while we were still trying to kill Rotan (we want the mount) and they started the Kromede fight.
He was able to solo kill Kromede while we were stuck outside of the dungeon and were not able to loot the box after as we had no participation.