"but Josiah takes out one bandit, making the other bandits flee. However, Kôštē thumps a bandit in the back with her staff as he runs past."- from GURPShexytime
Okay, then, so it's not just my PCs who try to kill all fleeing foes before they can get away?
To be fair, this group doesn't try to run down the fleeing bandits, albeit probably because they've got an active threat in front of them.
But this is the kind of decision that can come back to haunt you. If you never take prisoners and never let a routed foe escape, then you've taught everyone to resist to the last. Some groups will break anyway, but notoriously brave ones (like the orcs in my campaign) will learn that it's win or die and go into battle knowing that and act accordingly.
This keeps making me think I should give this rule a go.