There is actually an early indication that Miguel’s great-great grandfather isn’t really Ernesto de la Cruz. Although the picture of his ancestor has his face torn off, we do see that the man has a belt buckle of two guitars crossing (hinting at Hector and Ernesto’s double act). However, when we meet Ernesto, his belt buckle only has a flourish of decoration, with no guitars present. This not only identifies Ernesto as the wrong man, but also indicates that Ernesto cares about other things than music.