Runaan's Hurricane Bug for Pentakill in Ranked

I was playing ranked with my brother and he got a pretty ridiculous kill while using Caitlyn and it was because of Runaan's Hurricane glitching. I went back and reviewed the replay and it definitely shouldn't have happened. Someone can maybe tell me otherwise if they have an explanation. It just really really looks like it messed up and then some how got him a free kill. Not looking like it would have effected the course of the game, but was pretty hilarious none the less. I threw together this little video so that it would be easy for others to see and something to put on my little channel =) Enjoy

Here is the link on Reddit if you use that and feel like getting it seen there. https://www.reddit.com/r/leagueoflegends/comments/5hyih0/runaans_hurricane_glitch_for_pentakill_in_ranked/