Re-read my post, you didn't seem to understand it. Craig has not said he is Satoshi. Find a quote where he said that. You won't. He has always said it was his colleague.
Listen to the first few minutes of the BBC interview
http://www.bbc.co.uk/news/technology-36191165"You're going to show me that Satoshi is you?"
Craig - "yes"
Remember Craig is a lawyer. Remember how Bill Clinton explained in court what the meaning of 'is' is.
Craig has consistently claimed he was backing "the persona behind Satoshi" and was part of a group involved with Satoshi, so the above statement is consistent with that, without him actually being the man who developed the code of Bitcoin with his own fingers. The interviewer did not ask Craig "are you going to prove you are the man who wrote the code of Bitcoin?" which obviously can't be proved nor disproved by any signature since Satoshi did not sign the code of Bitcoin.