now they will say we have enough bitcoins for withdrawal after they bought at US500/btc (it went to US102/btc at one point)
what a nice trick.. now the problem is fixed and everyone is happy.
If that's the case, then I applaud them. Imagine if people reacted in other way and raise price instead of panic selling?
In the real world, if you have two supermarkets nearby, and in one of them roof collapses, berrying people underneath it. What would happen to the other supermarket prices? They would become higher.
People on the other exchanges should react in same manner. If there's a problem at gox, that means noone can exchange btc over there, that means we should raise price because people will be forced to buy from us on other exchanges.
that's why mtgox pointed the finger at the bitcoin protocol, instead of admitting it's their fault.... your scenario would work if mtgox say that they r collapsing etc.. but they were saying the bitcoin protocol itself has problem. In that case, btc could become worthless, so triggered fire-sell.