So the money quote is "My name is Dr. Craig Wright and under the pseudonym of Satoshi Nakamoto I completed a project I started in 1997 that was filed with the Australian government in part under an AusIndustry project registered with the Dept. of Innovation as BlackNet."
Googling BlackNet leads me to a post, apparently also by Wright, which describes BlackNet as "a system which appeared in 1993 and which allows fully-anonymous, two-way exchanges of information of all sorts" and attributes it to Tim May:
So it's not Bitcoin, and Wright's statement only says that he "completed" (not design, start or build all of) it using the pseudonym Satoshi Nakamoto, which may well have been used by many people, in classic "I am John Galt" fashion:
Well the coins from the genesis block can't be moved, so it would be difficult to prove on that basis. However there are approx 1m BTC owned by SN, so a movement of some of the early coins would be relatively trivial for the real SN.
Googling BlackNet leads me to a post, apparently also by Wright, which describes BlackNet as "a system which appeared in 1993 and which allows fully-anonymous, two-way exchanges of information of all sorts" and attributes it to Tim May:
http://ohmysatoshi.com/blacknet
So it's not Bitcoin, and Wright's statement only says that he "completed" (not design, start or build all of) it using the pseudonym Satoshi Nakamoto, which may well have been used by many people, in classic "I am John Galt" fashion:
https://www.wiley.com/en-us/I+Am+John+Galt%3A+Today%27s+Hero...