client locks the wrong champion in

If you are in champ select and choose a champion and lock that champ in, the client locks in the wrong champion. It happened to me with MF and Lulu in a ranked game. It happened also to a guy in this video (2:40-2:50): https://www.youtube.com/watch?v=TG5j-RexgbQ&t=190s I don´t know if and how the bug is reproducable but it must have a tiny chance to occur. A similarity between me and this guy is that the client locked the champion above the selected champion in.