think about this:
1. simon closes btc24 -> tell a good story
2. takes our bitcoins and sells them on other exchanges while the price is falling
3. waiting some days/weeks
4. buy back all those BTC for cheaper money
5. open btc24 again with all funds -> no harm to the users
6. profit!
could be. could be not...
Sounds like crap!
You bet on a falling price, handling a volume of 10.000 BTC for that would mean 10.000 loss/profit each $/ moved for example. Very very risky game, i would get him for suspicion of embezzlement if he'd do this!
Other point of view is, an eye is kept on all known wallets now. It will get someones attention sooner or later, and i think he is clever enough to know that!