From the Called Shot descriptionRunes of Victory
Craftsmanship: Dwarven, Elven
Item: Any weapon
When you attack using a weapon possessing this Quality you
score an automatic hit on a Gandalf and also on an Sauron result.
As a Sauron is always a hit, it means that it is now impossible to fumble even if no Tengwars are rolled (though the attack is still treated as a miss).If the roll result doesn’t match or beat the attack Target
Number AND the player gets a Sauron icon on his Feat die,
the called shot attempt fails in a catastrophic way, called
a fumble.
As it does not state that the Sauron is treated as a Gandalf, I presume that this still triggers the called short for the enemy.