Battle Afflicted Troops?

[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.

[Oversway]

I know with immortal commanders that once their side routs and they keep on fighting, that no enemy units retreat anymore.

I hadn't heard of this, but it may have happened to me in a recent game turn (using 2.15). Either that or the other side got really lucky with moral checks. Has anyone else seen this?