Warwick have bug

Here is bug when Warwick use ulty on same champ and after this Skarner use ulty on Warwick.

1. Warwick use ulty on same champ

2. Skarner use ulty on Warwick when ulty of Warwick is on

3. Skarner move and he moves Warwick

4. How Warwick moved he moves same champ (because he ultyed same champ)

I think how it is bug. When Skarnet use ulty on Warwick , Warwick ulty need be break.