what the lag?

okay i just finished a game as sona (practicing, gotta be good with dat skin :D) anyway on the last teamfight i got a massive lagspike, everything froze and moved like every 3 seconds or so, i died without even ulting. after that it was so laggy (while i was dead) that i had to leave the game and reconnect, but until then the rest of the team had died and they were knocking on our inhibs. i killed 2 of them but i died :/ so we lost due to 1 lagspike.