It’s not cheating, it’s a server bug. Nobody gains rank in the situation(at least I never heard of it). I don’t know the exact reason, but this thing seems to be quite often. Many strange things happen when the servers are unhappy, it’s a horrible bug, and before urban does something about it, I guess you’ll just have to get used to rank losses like these.
Once you enter a game and refresh your page, leave the game or never, time out or what ever it counts as a lose. And yes, it affects ranking so becareful when playing.
It in fact is not cheating. When it happens I suggest filing a bug report if necessary, otherwise there is little we can do. I feel your pain to, ranked matches are dangerous!