I had just finished killing Merchant Boggs, when another player, came running down the hall, and zombies started to spawn, only a few, but I was quite surprised to see another player there. I have heard of this happening before, but this is the first time it has happened where I can report it. The player said they just got the quest and were as surprised as I to see someone else in it. Esp. since the quest was now empty..
This happened today, at about 6:30pm GMT
And I do not think it is a recurring bug, as it has never happened before.(to me)
I was playing Finrick and the other players name was Legodia Melianacia. Very odd bug.