Riot wtf is this

He autoed before he W'd

Welcome to basic attack's lock on. If the animation is already started and they don't cancel it, you can teleport to fountain the moment it lands and still get it.

Keep in mind though, the timing on this is incredibly precise. You probably won't see it often enough to have to worry about it.

E is an enhanced Auto attack. You should be able to piece it together with this info.