Some ideas:

1. Maybe the owner of the 80k bitcoins is Satoshi himself.

2. Maybe someone lost the private keys years ago, and he just recently found them.

3. Is it just a coincidence the 8,000 bitcoins lost in the landfill by James Howell is similar
    to the number 80,000? Of course its ten times less than 80K but the numbers are similar,
    but off by just one zero.