When John Leonard, executive director of the World Swimming Coaches Association, described Chinese swimmer Ye Shiwen's gold medal victory at the London Olympics as "unbelievable," he didn't mean it as a compliment.
The 16-year-old's win in the women's 400-meter individual medley - where she swam the final lap faster than men's contender Ryan Lochte - has been tainted by allegations she's using performance-enhancing drugs.
China's former Olympic doctor Chen Zhanghao fired back, accusing zillion-time gold medalist Michael Phelps of doping. Which is only slightly below "I know you are but what am I?" on the list of lamest comebacks ever.