So I just spent a few minutes playing with Great Circle Mapper and while it's not exactly definitive (you get a static image, no zooming) it appears that leaving from Greater London and heading in a great-circle direction toward the northeast coast of Brazil, there are indeed some combination of your location and precisely where you point the phone that you either pick up Finisterre, metropolitan France, or Brazil. I suppose if you kept going you would pick up France again as in the territory of French Guiana.

Going from, say, Land's End, it looked a bit more likely to nick northern Galicia.