Are you eating your defense team? Feeding all the heroes in it to others for leveling is the most common way to accidently drop out of an alliance war that I know of.
Closing due to old age of thread. For new issues, please see: 📵 Disconnected During War Attack /Titan /Network Connection Problem Caused Lost Attack, Flag, and Heroes in AW / Scored 0 Points on War Hit Due to Dropped Server Connection / Game Crashed and I lost my War Hit [MASTER]