Gameplay: Hecarim E

Multiple times when playing Hecarim, I have been either unable to knock someone back with his E or they get knocked back in the wrong direction. Often I will click on someone with my E up and I will move to the opposite side of them, then knock them back, opposite of where I want them to go. Today I played a game where I went behind a Jhin with my E and tried to knock him away from his turret. Instead I knocked him towards it. I was behind him before I tried to click on him.