Annie's Q stun coding VS Vlad W and Fizz E

Okay, so is it suppose to keep the stun ability for Annie even if I dodge her Q with a playful/trickster or sanguine pool? It seems so slanted towards Annie, I mean she loses the stun if the Q reaches a minion but doesn't kill it; I mean in the case where the minion dies while the Q is in flight; but when she casts it on Vlad or Fizz and they go untargetable she retains her stun ready cast even though she just technically used the spell and it failed to land on an applicable target, like the case where a minion dies as I stated above.

It makes actually playing with timing and dodging that skill completely void, it's only a 4 second CD at most and now she still has her W to hit with when you become targetable.

Tl;Dr Shouldn't Annie's stun charge reset after casting Q and the intended target becomes untargetable, thus the spell does nothing just like when hitting an already dead minion.