I believe the journalist is focussing too much on one phrase (currency manipulator) without context or the entire economics.  
The plain simple fact, China does not manipulate its currency.  China sets its currency at a fixed percentage of the US dollar.  By definition China is not manipulating the currency.  However by doing so, the US is at a trade disadvantage with China because rising Chinese wages and inflation are not reflected in the currency rate and therefore the price of Chinese products.  i.e. one of several reasons China has a $347 billion trade surplus with the US.