[Gameplay] Ornn ultimate

Many times, in a critical moment, I will ult with Ornn to change a teamfight or something. Everything is going normal, the fire elementalist is coming at me normally, and I'm set up to knock up four people with the knock back. I hover their team, aiming it for a nice four man knock up, but when I hit r again, rather than hitting the elementalist torwards my team, he knocks it THE COMPLETE OPPOSITE DIRECTION!! Now I look hopelessly as my team dies and look stupid in the process, despite not doing anything wrong.

*Note: I believe it has something to do with the mini map, since it usually happens when i try to hit it in that direction, but it happens a few times in other directions.