Won a ranked game and received a loss!

In my most recent Jarvan game my jungler requested to swap to mid. Being a nice guy I did, playing J4 sounded fun. We get in the game and have an interesting lvl 1 fight and my Kat gets a couple kills to start off the game. GREAT Start! I finish my first clear and get a few ganks in and all of a sudden the team score is 7-1 and the power in my house goes off. I quickly fix the issue and come back asap to end up winning the game and to my surprise receive a loss in my promos. I've never had anything like this happen before except when I was learning then game years ago with awful internet. What happened here! and why am i receiving a loss for being a kind player with bad luck?