[Gameplay] - Yorick Bug!

Was playing an ARAM today and all of a sudden, the enemy team starts yelling at me. Confused, I wonder why until I notice that I had 2 W ghouls out at once. One of the ghouls had no HP but could still do damage, slow, etc. It even gave me CS when attacking minions. I could still summon more W ghouls with no problem. I have it recorded but the quality is really bad. I'll upload it if it is needed. Maybe it's time for a update?

EDIT #1: The ghoul stayed alive throughout the entire game. The enemy Syndra could also move it around with her W no problem. The video is currently processing.

EDIT #2: Here is the video. http://youtu.be/oJR6T-xVInQ