League of Legends: Teamkiller Tahm Kench

Ok so I have been seeing tahm kench killing teammates using a bug that has to do with his w and his ultimate heres you to reproduce it step 1: use your ultimate step 2: get someone to get in your mouth step 3: activate w and then it will think that it is a minion in your mouth so when you spit it out its like spitting out a minion projectile and can kill temamates and if it does it will say the following: game_announcement_onchampionkill_ally_you here is some proof from a youtube video thank you for your time to look through this bug i hope it gets fixed