Financial gain that simple really and he only made $1000.
It wasnt $1,000. It was $1,000 worth of bitcoins while the price was at $0.01, or 100,000 bitcoins. at the $17.50 price mt gox will open at, thats 1.75 million dollars.
You may be correct about the withdrawl amount (if pulled out before the immediate upward rebound, which would require fancy clicking). However, the $17.50 price is subject to the global market price when the opening bell rings irrespective of Mt. Gox time-freeze. All orders have been cleared, that means Mt. Gox is an entirely new market that just happens to have a bunch of accounts and currencies in it (we should hope).