Game Mechanics: throwing knives stuck in a wall / tracks target indefinitely

[Locust]

I threw a knife at a centaur through a wall and my throwing skill went up...
this made me curious because I was expecting a "you cannot see your target" message

I went closer and noticed a throwing knife stuck in the wall. Tried clicking on it but it wouldn't come out. So I stood back and threw some more. Those throwing knives seemed hell bent on getting to that centaur. Eventually someone else pulled it and the knives followed. Didn't see any damage in the log but it may have been too far away to see. No agro at least.

proof:

https://www.youtube.com/watch?v=1AyGEBGJJ0o