No matter how "expected" his score might have been, Santaolalla was wise enough to know that in music, the slide guitar makes about the saddest, "achiest" sound this side of the cello. It's an ache you couldn't put into words. It wasn't merely going for some kind of impressiveness, but exactly suited to the film, really adding another dimension, and exactly the right one (maybe "suited" a way of saying "expected" or "predictable" but with an opposite bias?). Anyway, that slide guitar won my vote.