Syndra Bug

I'm not sure if it was my mistake or not, but I thought that I noticed a bug in earlier. When I would go to Q-E, or W-E, but the kind where you cast your E before the animation for Q or W finishes, I noticed that the E would cast completely in the wrong direction. I also noticed that one time I tried to W to throw an orb and then Q on the same target in a similar fashion (before the animation had finished) and my Q ended up down and to the right of where I had cast it. I'm playing on smart cast, and so I don't see how it could have possibly been a user error. I was doing this as quickly as possible to try to stun a target, so maybe that had something to do with it.. I'm not sure. Either way, I'm relatively certain that I did not move my mouse while in the middle of trying to cast two spells that quickly.