We can't know what the press might have been four years ago, but Safari being anything but built "from the ground up" doesn't sound right to me.
Just as OS X's open source Darwin kernel is a derivative of the XNU open source Unix, Safari's Webkit rendering engine (a fork off of the KHTML rendering engine stream), Nitro javascript interpreter, and other key components are all open source technologies. Apple has, of course, modified and tuned them through various versions of Safari, but the open source code is still there and Apple frequently releases their modifications back into the open source stream. So Safari may have been
assembled from the ground up, but the components did not neccesarily originate with Apple.
When I switched to Mac (2010), I read some bad press about Safari being a poor reworking of I.E.
Whoever said that was badly informed. Safari and Internet Explorer have never had any common components. While Apple happily adopts and uses open source material, Microsoft has only recently admitted that open source is a four letter word describing a bodily function.