Dont worry about your rating.
Think of it this way, stuff like that happens to everybody. If half artificially adjust their ratings down, and the other half do not, then you are REALLY screwing with the rating system, which is only there to determine your strength relative to other players in the same pool.
If you are a 1200, and by some error you find yourslef at 1800, just play some games, and you'll soon be back to your real rating. Glitches aren't permanent, they come out in the wash.
OK, so I don't play a ton of games on this site, but I usually have a few going at a time. I noticed that one of my opponents closed his account, but his game is still showing on my page. It's a 7 days per turn game so maybe he will reopen the account soon, but if he doesn't, will my rating go up after he voluntarily closed his account? I feel like that's kind of cheap.
But I feel like my only other option would be to resign one of the games to keep my rating close to where it is now. I don't really want to do that either, posting a loss for nothing. What would you do?
I guess if it were a real tournament and my opponent withdrew, I wouldn't protest. But I do still feel a little cheap, possibly adding to my rating after winning two games that are only 3 moves in! Does this happen often?