Slitherine

I understand that on normal game , one side loses the heart to fight when enough of its units are routed.
However I still don't understand when this check in done ?
Is it done at the end of each turns or only at the end of the "routable" side turn ?

I'm asking because yesterday I was playing against the computer and even thought at the end of my turn (after rallying) the score was 22% 51%(-29%), the computer played is full turn before losing heart.
I've noticed that happening a couple of time ...

The victory conditions are only tested at the start of the human player turn. This means that in SP games the AI will play its turn before the victory conditions are tested at the start of the next player turn.

That makes sense. Thanks