I think it is an exploit, there was no countdown to there not being enough players or anything. I believe they have found a way to terminate the wz as a win for them.
So I was playing Novare Coast coast today and encountered a bug where even my team capped 2 guns at the start then we lost immediately after doing so. Here is a screen shot to back up my claim too. This is a serious problem.
http://i.imgur.com/e7pgL.jpg