You can't be serious. Dan Rather and his network CLEARLY had it out for George W. Bush. They WANTED him to lose the 2004 election and wanted to get that story out as quickly as they could. This wasn't "incompetence," it was bias. Their hatred of George Bush made them air a story that wasn't authenticated and they got caught. Not only that, but as recently as 2008, Dan Rather STILL was saying he didn't do anything wrong. So, please, give me a break.
edit..
I'll say that it was imcompetence AND bias. (edited a few days after I originally posted this reply)