[Endoperez]

I think it goes this way, but I don't remember the exact numbers:
Only one side can rout through normal means (failed moral). However, if the battle reaches the 50-turn limit (if it was attacking) or the higher limit (if it was defending), it will rout. If it fails to do so (paralyze, berserk, fatiqued etc), the maximum limit hits in and everyone dies.