Zac's E seems buggy

The last game that I had played with Zac had an annoying bug with his E. Every so often (not quite sure on how often it happened exactly, but it happened consistently enough for me to estimate it at about 25%) no matter how much I charged the E or where I put the cursor, Zac's E would just land him an inch away on the right. I could have it at full charge and pointed at the very end of the cone's range, but it would just plop me away from where I was pointing.