The rules are vague. If a Lieutenant flees an outdoor encounter, what exactly does the party get for rewards?

Beldorn

I think I was asking this when we had our first encounter because it isnt clear.

Pretty sure I ruled it as the heroes won the encounter and they get the treasure.

Yup, that's how we play it too: the heroes get the loot for a won encounter, but not the Conquest/Gold for slaying a lieutenant.

Here it is from the book:

Fifth, a lieutenant may flee off of the board through an exit
space just like a hero. Doing so ends the encounter in a party
victory, and moves the lieutenant to the Overlord’s Keep. Any
Quest Item the lieutenant was carrying is left behind for the
heroes to take.

So they're entitled to the gold from the encounter, but not any rewards for the Lt.