Rek'Sai tunnel

So playing a ranked game earlier today and a Rek'Sai tried to tunnel out of a team fight when she was in the tri bush next to gromp on red side. She started the animation, but died before she dig under. Now usually I see this and the tunnel wouldn't spawn. Well this time the tunnel stayed but did not complete itself. So I couldn't get rid of, but she could still ult to it It looked as if the second part of the tunnel got stuck in the wall in river bush, which we had vision in. also it did not go away the rest of the game. Rak'Sai had the pool party skin if that makes a difference.