On page 24 it says
Victory X
Some enemy and location cards award victory points
when they are defeated. When such a card leaves play,
one player should place it near his threat dial to remind
the players of the victory points when they are scoring
at the end of the game.
In the FAQ it clarifies that shadow cards "leave play" at the end of the combat phase.
The first sentence is poorly written since a location cannot be defeated, a location can be explored, only enemies can be defeated. This sentence can't really be taken literally because you could never get victory points for locations.
So it comes down to how we should interpret "such a card" in the second sentence of the defintion.
Using common sense (a danerous thing to do), "such a card" therefore either means " a defeated enemy card with victory X or an explored location card with victory X " or it means " a card with victory X ".
In the first case you wouldn't put Hummerhorns in the victory display if it was revealed as a shadow card, in the second case you would.
Has there been an official ruling on how we should be interpreting this?