http://www.bbc.co.uk/news/technology-36168863If you look at the interview on bbc, wright's body language and the way he speaks is very telling.
First you can see that he forces himself to not make eye contact with the camera. He is looking on both sides and down but never at the actual audience.
Then he has a very angry look, this is also done on purpose. It is easier to keep your composure and seriousness with a angry face than an happy face,
At the beginning of the video he kept starring at his screen, that was done to not mess up his intro ( which is the hardest part to do when you tell a lie). It is also much easier to lie starring at a screen than looking at the audience or even the journalist, that's why when he said he was going to sign it with satoshi's key he made no eye contact whatsoever.
Then there was a slip up he said the monkier instead of moniker ( this is not a pronounciation error, this is stress induced error)
Also you can see that he is speaking in a very unatural way, almost robot like as if he had already thought what sentence he was gonna say. People that speaks like that are affraid of not controling what they will say.
Then the journalist says " so you gonna show me satoshi is you" and he said straight away that some people will believe some won't eventhough that wasn't even the question ( this shows he is not confident and insecure about what he is about to reveal)
Then when asked why he kept this a secret for so long he didn't actually answer the question, went on a tangent and spoke very defensively
Finally he said i will never ever be on tv ever for any interview EVER again. Insisting on the fact that he would never do another interview. No wonder why , lying in front of the world is not an easy challenge as you can see from the video and he would rather not do it again.