Client - Post Game Lobby, not responding?

No not responding screen, can see everything happening, can't do anything. I wanted to report the blocked riven, but when i clicked report button, client went white tinted like it was about to say not responding, but nothing came up, and i could still see the people leaving. http://prntscr.com/9hpkmq (I really wanna report that riven please, flamed for me playing trist jg, and just kept trying to chip away my confidence by repeatedly calling me bronze trash, and falsely reported me for offensive language when all i was doing was disproving his point)