I run a into quite a few object placement bugs lately: Wrothgar has some objects "disconnected" from their original places and floating in various altitudes: platform pieces in the city, jugs and other ritual objects way above the altar on Kurog's funeral, and other hickups.
Now I found a tree on the shore of Halcyon lake in front of Mournoth Keep floating as well so it may not be DLC related as I suspected so there's a chance for other examples anywhere.
I wonder if the next server maintenance would fix these...