Lux unable to use her E

With Lux if you land your E on an enemy after you die you will be unable to use it through the rest of the game.

1. Throw out your E
2. Die
3. Your E self detonates on an enemy (in my case the enemy didn't die but had about 150 hp left)

After you re-spawn the icon will be grayed out and you wont be able to use it.