Pinecast has no way of knowing exactly where a listener is from, though we use their IP address and other information to estimate their approximate location.
There are a number of reasons why the country may be wrong for a listener:
The IP location data that we used to infer the country is wrong.
The user is using a VPN or a proxy server.
The user is very near the border of two countries.
The user is using a service like Tor.