Mine is similar to the OP, had both players drop out on Archon Priest, and 2 join me when I had the boss down to like a sliver of health. One kid kept trying to melee the boss to kill him, he died like 6 times. So we down him and get to the rewards screen. I had 150+ kills, like 10 revives because both of these guys died a ton when they came in, they had like 15 kills each and 5-6 deaths each. I get 2 blue engrams, one of them gets a legendary engram and a new ship, the other gets a legendary engram and The Last Word. I really wanted to throw the controller through the TV at that point, but in all honesty I'm kind of used to it by now since this happens to me all of the time.