I just read the original article:
http://mag.newsweek.com/2014/03/14/bitcoin-satoshi-nakamoto.htmland it seems to fit nicely, but everything mentioned is very circumstantial. Also, I am sure if anything didn't fit with the narrative it was dropped from the story.
The video also doesn't seem to be much validation either. "I never communicated with bitcoins." That would be a very weird way for anyone on the project to talk about it working on it.
Nothing is either proved or disproved, and good luck reading anything useful into his body language.
In the end, yeah, there is a darn good chance is he is the founder, but it is very inconclusive.
If I could pick someone to be the founder of bitcoin, this guy would be it. He is a humble sweet old guy with a penchant for collecting model trains and his dad was a Buddhist priest. So many people involved in bitcoin are pricks, so for the good of the currency, I would be happy if it turns out that this is the guy in question and not someone else.
I say someone should talk to him, and even if he isn't the real Satoshi, we ask him to take the credit for it, and we will adopt him as the founder. In exchange we can all chip in and buy him whatever supplies he needs to keep working on his model railroad.
As far as properly denying anything, the only way I could see it happening is if Dorian was on a live video feed that couldn't be faked, and the real Satoshi signed something time dependent and unpredictable such as the current value of the S & P 500 at the same time. I would call this the Superman Defense as Superman and Clark Kent could never be seen at the same time. This would of course require some collaboration between Dorian and Satoshi, and could only be faked if Satoshi let someone else use his private key (which would give that person the power to pretend to be Satoshi).
Alternatively Satoshi could publicize his private key thus making it impossible for any claim to be Satoshi to be verifiable.
And of course to remove the risk from Dorian that stems from the fact that every piece of scum in North America now "knows" that there is a defenseless billion $$$.
Now that is a scary thought. He is going to need some serious protection now, or for safety sake, if he is Satoshi, he might want to destroy those bitcoins in a public way. For people that think that is crazy talk, countries have been invaded to seize less money. He now has a billion dollar price tag on his head to extract the information out of it.