Reporting a player

Hey so we were held hostage in a game. Jungler said first team to get first blood would win and he would make sure of it. Called it the "first blood challenge". Sure enough we gave up first blood so we lost and he made sure of it. I, of course, figured this went against the summoner's code and reported it, but nothing came of it. It's very clearly in chat, he/she wasn't shy about it, so why is this not punishable? Does the mass number of reports per game of people reporting because they lost prevent actual punishment?