Jun Jun didn't choose to join Xi Wei for round 3. The rule was changed and enabled Qi Wei to sucessfully get Jun Jun. Worse still, even though Jun Jun came in first in the 2nd round, she was told she cannot be the Captain since she is now in Qi Wei's team. Thus that fell to Liu Xin. But Liu Xin agreed to be in Qi Wei's team when approached. So Jun Jun was made to be a 'puppet'...JMO
