Xiao Qiao defects to Cao Cao

The event where Xiao Qiao defects to Cao Cao is a fictional event from the movie Red Cliff, directed by John Woo. The event takes place during the Battle of Chibi.

When all preperations are made for Zhou Yu's fire attack on Cao Cao's fleet, Zhuge Liang notices the wind is not in favour of the plan. Zhuge Liang predicts the wind will change, but only after a couple of hours. Xiao Qiao overheard the discussion and sneaked out to Cao Cao's camp. Cao Cao, in awe of Xiao Qiao's beauty, accepted her into his camp. While the forces of Sun Quan and Liu Bei were waiting for the eastern wind to blow, Xiao Qiao bought them time by keeping Cao Cao occupied, by telling him everything she knows about tea.

What happened historically?

 * Historically, Xiao Qiao (or Da Qiao), were not one of the reasons for the Battle of Chibi.
 * Historically, the eastern wind blew at the date of this battle and buying time was not needed.