It's really unfortunate that here in America we can't even trust our own government to tell us the truth about such things and to do the job we pay them and elect them to do - serve us and our interests.
It's doubtful whether there was US involvement. North Korea has a very small amount of bandwidth for a country and a small number of ip addresses, almost anyone with a relatively small amount of resources or the average hacker group could have easily ddosed it. The US usually goes after much bigger fish.
I doubt the US was involved myself. I think it was just an act of panic - quickly reversed when the little man realised that it would become world news and raise even more questions about the regime.
Quite improperly said "Internet". What they have is a much lesser version of that. One that's available to the whole public of course. We don't know what Kim does with his time at home... it's called Intranet there because the network operates just within the country. Unsurprisingly though, they aren't able to sustain even that. xD
