[GAMEPLAY] Sion - Perfect control of ult

Sion seems to be able to perfectly control his champion movement during his ult, as if he was simply walking, without the turning restrictions that the Unstoppable Onslaught is supposed to apply. What I experienced was a Sion on the enemy team dashing at me with his ult. I flashed over his head, to be in his back, and he flipped over at 180 degrees within a centisecond, smashing me with his ult.

I do not know at which frequency this occurs, but it seems to be specific to a kind of hacking to what I read on the very trustable internet, and does not seem to be very frequent due to the lack of attention this bug has received.

I do not know how to recreate such a bug, but then I found out other posts on this thread reporting the same bug, and none has gotten much attention. I hope this can be fixed, as it is clearly broken. Thanks.