A properly-designed script should not connect to the SHOUTcast/IceCast server's audio feed to test for connectivity or poll for status information; rather, it should simply query the SHOUTcast/IceCast status pages for such information.
Centova Cast does not treat status page hits as visitor sessions, so such hits will not cause this problem. However, if a third-party script requests the SHOUTcast/IceCast server's audio feed, there is no way for Centova Cast to distinguish it from a legitimate audio player attempting to tune in to the stream. Accordingly, such requests are interpreted as visitor sessions and are thus added to the statistics tables.