[The Panther]

I have seen this before also, where both armies esentially rout in the same turn, or maybe the following turn or two due to poison damage. But I have never seen an army rout several turns later after a full-out retreat by one side. Immortals and berserked units seem to always count as fully retreated in this, even though they stay to fight to the end.

Were there several turns between the enemy routing and your army routing?