For clarity here, again - the bitcoin system was not hacked or breached. What happened with MtGox is basically a very advanced combination hack against their system.
This hack was a combination of:
* Social engineering against MtGox in the way transactions were handled to cause the same transaction to be sent multiple times.
* Technical, timing sensitive “hack” to change certain aspects of transactions *before* the transaction was committed to the block chain.
MtGox was basically using certain mutable elements of in-flight transactions to speed up the process of transaction management instead of looking for the transaction to be included in the block chain with multiple confirmations. With any of the crypto currencies, it is intended to wait for at least 6 confirmations after a transaction has been included into the block chain to consider the transaction to be complete and immutable, particularly with any high-risk transaction.
MtGox’s losses were not truly the result of bugs in the software, but bugs in their process.
You can chop semantics all day long but once the knowledge hit the street Bitcoin prices were never the same and now they are well under the value they once were.