[GAMEPLAY] Lucian bug

I recently experienced a Lucian bug. After I used Q, and clicked Q immediately after, the second Q was cast. It DOESN'T work all the time (propably). It happend to me twice during ~40 minute game. Didn't try to reproduce it myself then, I didn't do it intentionally. It is hard to tell me really how to reproduce, I believe it is something like:

1. Use Lucian's Q
2. Immediately after or even during the animation use Q on another target
3. Another Q is cast PS: Once it happend immediately after my E cast, I don't know if it does matter.