Rageborn Mundo Skin bug (GAMEPLAY)

In a game a few days ago I had to go up against a Dr. Mundo in bottom lane as he was supporting. This Mundo had the Rageborn Dr. Mundo skin on and every time he threw a cleaver it would be completely invisible to our team. You would see a throwing animation but no actual cleaver and if you were to of gotten hit by it you would just take random damage and be slowed. I believe this was a big reason for my team losing that game as the Dr. Mundo player would sit in a bush and just chuck invisible cleavers at us without us knowing where they were coming from. I haven't been able to reproduce this as none of my friends own the skin, but I think it should at least be know that this might be a bug in the Rageborn Mundo Skin.