Regifted Amumu Bug (Gameplay)

In one of my games I was playing Amumu and I was using the skin Regifted Amumu. It seems when Amumu dies with that skin on and get revived by a Zilean ulti, the skin loses its ribbon??? I was able to view this on the replay, I as well saw it during my game and the person I was duoing with saw it too. If you want to do this yourself just make sure you are in a game using the Regifted Amumu skin and have someone play Zilean and revive you when you die. I'm not sure if this happens with Guardian Angel too but yea. Happens with Zilean ulti.

Screenshot Gyazo thingy: https://gyazo.com/0397a7bdee458d5ec643999ccb16a00b Youtube Video of the replay: https://www.youtube.com/watch?v=t3YtIxb1Kms