The disruption in service may have been at your end, not necessarily from BGA. In general, it isn't the best idea to play real-time when you're not sure of the stability of your internet connection. That you were disconnected but it just looked like your opponent wasn't playing has happened to many people here (myself included), and you're unlikely to get your penalty reversed. If a player stalls out like that in future, I'd recommend refreshing to make sure it's not actually your connection that's had an issue (especially if you are getting messages about being disconnected).
In general, a karma loss isn't that big of a deal - your first one is only 10 points and doesn't restrict you from anything on the site. Yours was 20 this time because it was your second in as many days. Still, a karma rating of 70 isn't going to exclude you from much, and you just need to play games and finish them within the time limit (1 pt per game finished). Some people favour playing short games to regain their karma (eg. Can't Stop), but I personally say just keep playing whatever interests you and your karma will return. If you're worried about it, you can always play some turn-based games to limit the possibility of having any other penalties from accidental disconnection (though the stability of your internet, or at least your knowledge of it when choosing to play, is within your control, and that's why you are penalised when it fails you).
