Visual and behavior bug on Exiles reach

https://www.wowhead.com/quest=59938/down-with-the-quilboar

At the end of the quest when you kill Geolord Grek'go, insted of the Goblin npc what appears is the gnome of the alliance and few steps ahead to enter the other zone you'll see another copy of the gnome levitating in the purple aura, check that plz