What - the 'radio telescope' used by the Europeans isn't "frequency agile" and able to be tuned to the 'downlink' frequency used by Spirit - thereby validating the 'radio path' from Mars back to Earth?
It's my understanding the purpose of the test is to simulate as closely as possible, using Spirit, the signal frequency and strength they expect the Beagle 2 presents from the surface of Mars (if it's transmitting) and try to detect it with the radio telescope on Earth. It's an attempt to remove as many variables from the test conditions relative to the real objective and prove that the problem rests with the Beagle 2 rover and not with the search methodology.