[Gameplay] Vel'koz max range E + flash interaction

On Vel'Koz, If you cast E, Tectonic Disruption, at max range and then immediately flash out of range before Vel'Koz completes the cast animation to send out the projectile, Tectonic Disruption will not fully cast as the projectile is never launched. The initial circle indicating a cast will appear, but the explosion/damage/cc will not occur. Tectonic Disruption then goes on cooldown.

1. Cast E at max range
2. Immediately flash further away, before the E cast animation sends out the projectile

I'm fairly certain this bug has existed since release. I tested this extensively in practice tool - as long as you flash away immediately, it is 100% reproducible every time. I included a link reproducing the bug in practice tool.

Edit: Here is an example of the bug happening in a real game last year. If not for the bug, Cassiopeia would have died to Vel'Koz instead of Vayne. Another common situation where this bug occurs is casting E on an ulting Twitch and flashing away.