You submitted this as a bug report. I wrote a nice reply to you explaining why it happened, but your e-mail address bounced. You should fix your e-mail -- it's frustrating to write a long email to just get an "undeliverable" reply.
Anyway the game is here: http://warlight.net/MultiPlayer?GameID=4762043
What actually happened was that you got booted (the game had a 5-minute auto-boot, so if you were away for 5 minutes you'd automatically get booted.)
If you look at the settings of the game, you'll see that booted players are replaced by an AI. So once you were an AI, the AI is actually what surrendered for you, which is why it said you surrendered.