Well, I don't know if it's mislabeling necessarily. At this point, magical realism isn't confined to colonized people--that's just where it started. I think it was Garcia Marquez that coined the term--and the technique is most notably used by South and Latin American writers. But then it spread to India (the term--not the style--the style was already present), and then the technique sort of started appearing in literary fiction all over the place. For some reason I can't think of any stuff from the US or UK off the top of my head that I'd call magical realism. But I do think of the movie Amelie. OH! And LA Story! LA Story is the perfect example, actually. That's magical realism done by a a white dude. It's like isolated unexplainable (magical) incidents that are treated by the story (and often the characters as well) as completely normal--all taking place in the completely knowable, real world. So, everything's normal and then one day a traffic sign starts talking to you. Or everything's normal, and then the boy who lives a few houses over gets carried away by butterflies and never returns. And the normal stuff just continues on.

Fantasy is like, whole other make believe world. Or it can be in this world, but with circumstances completely altering it--ie, vampires live among humans or something happened and the world is completely flooded.

So I don't know if the books you're thinking of were marketed in a particular way that might not have been true to them... but that's sort of how I distinguish those genres.