The game sometimes crashes when attacking just before the 'Go Home' screen appears. This leads to complete loss of crowns, coins and spellstone won in the battle. On restart, sometime you have the complete army intact and sometime the army too is all gone.
Has happened to me more than 20 times. Barring a few in most of these 20 times I had won the battle. Would have lost around 100 crowns due to this.
The attach log that is maintained is that of the attacks on the town and not that of the towns that you attach. It is very difficult to remember who you were attacking too.