you probably did something wrong it working right..I suggests you read your log and see what you did wrong and then try to redo the instance again.Did you loot him because you wont get it unless you loot him.
This quest has a bug. I have done this and have the item in my inventory. A guild mate wants to get caught up to me and we ran this quest the day before yesterday and he got nothing. We went on to finish the quest and came back to the area and still nothing. Yes we looted the body and he got nothing. Last night after getting word back from EA we ran it again like they said and it was the same dang thing. The quest is bugged. Not sure how many more times he will be willing to run this before he says to heck with it. With the amount of threads about this EA might want to look into this.