I don't know where you got that 80 million STEEM figure. Go to steemd.com frontpage (or fire up the cli_wallet) and take a look at the following numbers:

• virtual_supply : Total STEEM including Steem value of Steem Dollars and Steem Power (104.7 million)
• current_supply : Virtual supply minus Steem Dollars (104.5 million)
• total_vesting_fund_steem : Total STEEM value of Steem Power (101.8 million)

The withdrawal is correct, it's just measured in satoshis and not labeled properly by the website (although to be fair it's not properly labeled internally in the C++ backend either). It should be 1,000,000,000.000 000 VESTS, or exactly 100 million VESTS. There are 451,397,813,634.071401 VESTS in existence (that's total_vesting_shares) which collectively own a pool of 101,832,386.827 STEEM, so 1 million VEST is worth about 225 STEEM.

Powering down takes place once per week for 104 weeks, so his request to power down 1000 million VESTS means 9.615 million VESTS will be powered down every week.

The numbers are right, it just takes a careful eye for detail to understand how to interpret them properly.