Another coincidence happened in 2010.

Satoshi secretly fixed the poison block issue within Bitcoin by locking the block size at 1MB. He discovered it and fixed it before anyone noticed. This makes it seem like Satoshi was actively poking holes in the protocol with security in mind.

Coincidentally, in 2010 Len was giving a number of talks with his wife regarding protocol design and security.

Seems like the pool of people with the right expertise, area of study and skill set gets smaller and smaller... to the point where N=2, and that's Satoshi and Len.. or maybe N=1.