Lucian Bug on passive. 6.22

I have been playing an excessive amount of Lucian in the past week in patch 6.22 and have discovered a bug with his passive. His double tap when you last hit a minion prioritizes another minion that can be last hit or at random. However, if there is no second minion to last hit the double tap fizzles and he does not fire at all. I cannot give an exact number as to how often this occurs but it does occur. If I am mistaken please let me know.

Thank you!

-A friendly phylol.