[Gameplay] Vlad pool stun delay

I am not sure if this is considered a bug (never played Vlad so I am not certain how his pool should work exactly), but the following happened in a recent ranked match:

I was playing Renekton and attempted to flank the opposing Vlad. I flashed onto him and used my stun (W) and the animation completed. At the same instant he pooled and began moving away. Once his pool was gone, he was stunned.

I assumed that the stun should have occurred before the pool or not at all. Figured I would report just in case.