Oh, isn't that just typical
Yulia apparently did something to her back, and the doctor ruled she had to retire from the contest. So she had to sing (Prosti Za Lyubov) while Jerome Blanchard did a solo spot. While it's excellent to watch, it's not what anyone really wanted.
As far as I can gather Yulia could well have been the eventual winner and the judge certainly seemed to praising her. I think she was invited back to take part in the grand finale, although someone with a knowledge of Russain would have to confirm this - I'm just going on body language.
http://uk.youtube.com/watch?v=rLlufa6cGVo (the song and solo dance)
http://uk.youtube.com/watch?v=VNgRh3UUzjo (the judge's speech)