Kassadin has a combo bug

When you rift in one direction and then apply that screamo cone AoE (No idea what it's called), Kassadin will cast the cone in the direction he was originally targeting, which is usually behind him.

Let's say that he puts his mouse over Akali, shifts directly behind her and casts the AoE. The AoE will not target Akali's direction, but will target behind Kassadin when cast in the direction which he came from. My friend has performed this combo many times and only recently has the AoE scream cast in the direction opposite to which he shifts after combo-ing.