It sounds like you don't fully understand how a lagswitch works. If you are using one it affects YOUR connection to riot servers, which gives absolutely no advantage. If the game was hosted by a player or players, then a lagswitch would make a big difference, but because riot hosts all games on their servers, you can only dc yourself, giving your opponent an advantage.
However, there are other methods of interfering with someone's internet connection, DDoS as one example. But you have to know the end users IP address, which is not very easy to get. In any case, you would need actual proof for riot to take any disciplinary action, and its not really their fault anyway.
The most likely scenario is that you got unlucky, which sucks. Sorry about the game, but hey, you got a quadra. Thats something right?