The same thing happened to me about a month ago ( even before the release of the new champion Vi )
We were playing in the Summoner's Rift.. losing ( so it wasnt that bad of a bug ^-^ )
Someone in our team got a kill and the game disconnected. Since i was over skype with another friend, he told me he also got disconnected. We both tried to log out and back in, but no Reconnect screen ever appeared. Both checked the match history but it wasn't there, as if the game never existed.
We facepalmed for a bit.. thanked god for existing (when you're losing a game, only god can come up with this kind of bug)
I don't really remember what champion i was using, but at given time i only used Nami/Fiora/Miss Fortune, and my friend xxzuzaxx only used Fizz.
Hope it helps getting rid of the problem.
also.. dude, you gettng that epic shutdown, and the game disconnecting, letting amumu crying on the screen..
add some dark stuff and you got a sweet creppypasta.. xD
Oh wow.. I just accepted the summoner's code ^-^ that's sweet Riot. GJ