6721,
First, you're complaining about a politician claiming not to know something. Politicians in both parties deny knowledge of things that go wrong unless they are sure that their knowledge can be proven, which is extremely rare. That happens all the time. The public expects that, and they pretty much are OK with it. Sad, but that's just reality.
Second, I'm talking about the political ramifications, not what I personally believe. My personal belief is that the website's failures were known by Obama before it was rolled out, but that's speculation. I don't have proof of that, but it seems highly unlikely that the site wasn't tested prior to launch.
However, the dropping of coverage was absolutely known by Obama years in advance and before the 2012 election. It was an indisputable and conclusively established lie. That's a big deal. Furthermore, it has much bigger repercussions on the public. Both reasons are why this issue should be front and center in 2014, not the website.