I've just taken a bit more of a look at the photos. I do not see pale eyes in this bird, in any of the photos, but that's not the most important argument. In Santiago the most common birds would be Chimango and Harris's Hawk, less commonly Variable Hawk and BC Buzzard-Eagle. Mountain Caracara is pretty rare within the city proper.
I agree it's awfully hefty looking and coloration is poor for a Chimango. Coloration and structure are better fits for a juvenile Mountain Caracara, or a Harris's Hawk. Mtn Caracara is less likely based on location and the pale throat looks problematic. I will still say there's no way it's a Variable Hawk or BC Buzzard-Eagle. Both those species have huge secondary bulges and a very particular wing shape that is quite pointed in the primaries.
I haven't really really looked at this a ton, and it still gives a Caracara jizz, but I think on the combination of factors a juvenile Harris's Hawk is more likely. That lack of secondary bulge in the wing, though, really does throw you off.