When everyone drops at the same time, that means that you are one that actually dropped. They all lost their connection to you, and you were replaced by an AI in their game. You, however, lost your connection to all of them, and had all of them get replaced by AI's in your game. Apparently DG does not let you know this and lets you continue to play against AI's despite the fact that it's a fake game and you are going to get a loss on your record. 
