Fleet footwork works without hitting

At 100 FF stacks, if you try to hit a minion and it dies right before the attack happens (i.e at the start of the animation) you'll still proc FF, gaining both the heal and the bonus ms.

I want to highlight somethings here:

1. This doesn't happen with or
2. This mostly, if not only, happens in early game as the attack speed growth makes the animation too fast and is almost always complete.
3. In case this is champion/skin related, I play with pulsefire Caitlyn most of the time and it happens frequently (I don't miss that much cs though xD)