Clicking accept invite while already in champ select = dodge

Basically the same as title. I was in champ select lobby already and a friend invited me. I clicked accept cause I was bored and thought it be harmless. I figured it would say can't join because I'm already in a game set up or just ignore it. Instead after a brief delay I was kicked from champ select to menu. To top it all off I got a game dodge penalty. RITO PLZ