Malzahar's e on cooldown without casting [GAMEPLAY]

Occasionally, when his e is cast when a minion is very low (and, I'm guessing, dies before it actually GETS the e on it), it goes on cooldown without being cast. The minion on whom it was cast dies, but it doesn't jump to the nearby minion, meaning that the e goes on cooldown without having any effect whatsoever, or even appearing on the screen.

This also seems to happen in jumping from one minion to the next; if it jumps to a minion but the minion dies while it's jumping, it just disappears, and doesn't appropriately jump to another nearby minion.