As I was advised, the location search is entirely reliant on Google maps, so the fact that the search may indicate a different country as the first search location (unless you specify e.g. "UK") it is not controlled by the theme. Basically it means that people have to be more specific if they search and don't get the correct location as the first result.
Our team are investigating whether or not anything can be done to effect this from the JobRoller side, so whether or not this will be possible is yet unknown. If a confirmed "fix" can be found, I will be sure to update here. For the time being though, it's not classed as a bug in the theme, since it is related to an outside function (i.e. Google Maps).