How did Shiwen?

With each incredible performance of modern Olympic times, the question of doping is raised. Past scandals broke both records and our trust, and exceptional performances are burdened with the possibility of drug cheating.
The London Games have claimed to be the cleanest ever, but some performances have still left us wondering about the possible use of illegal ergogenic aids, specifically banned drugs. The 400M IM final is one event that raised doubts over the legitimacy of clean athletes. 16 year old Chinese swimming prodigy, Ye Shiwen, took her second gold of this years games in the event but sport scientists and experts have downed her performance. She swam the race in 4:28.43. The freestyle leg from Ye Shiwen was extraordinary and set her up to break the world record in the 400M IM. Her final 100 meters was faster than Ryan Lochte's, who won the mens' 400M IM. She exploded in the freestle leg and her final kick showed she had much in reserve coming into the last 100 meters. Accredited sports scientist Jonathan Dugas said that such a kick "goes against everything that we know about how athletes pace themselves at that level." Shiwen swam the freestyle leg 16% faster than the pace of her other three strokes, whilst her competitors swam only 10% quicker. Her time in the final showed a 5 second improvement on her personal best.
Has the world's media been too quick to doubt Shiwen's performance? Have they found her guilty until proven innocent? Was Shiwen's 400M IM an extraordinary case of a young athlete stepping it up on the big stage? It is not unheard of that a swimmer around 16 years old has a large improvement during that age. The natural development of the human body would have undoubtedly played a part in such an exceptional improvement on a personal best time. Ye Shiwen provided a negative drug test result under the most sophisticated testing ever, and this information cannot be ignored. But it is also said that the cheaters are one step ahead of the testers. Is it possible that China has decided to win at any cost? The People's Republic of China is an unquestionable Olympic power house, and this year has shown incredible improvement in the pool. The London Games have seen China improve from no gold medals in the pool to seven. Is such an improvement across the board due to sophisticated doping or incredible training and dedication? Whilst doping results will confirm the latter, common sense and past results may indicate the former.
Personally, I want to beleive the romantic tale of a young girl who stepped it up to the world's best and took away an extraordinary gold medal on the Olympic stage.