This would have all been avoided if MtGox had transferred its coins to a new wallet after the 2011 breach. I guess they assumed that any attacker that got access to the private keys would have immediately emptied the wallet, and the fact that this hadn't happened proved that the private keys hadn't been compromised by the breach.
I have to admit, that is a reasonable assumption. This may show the limits of the usefulness of heuristics, and the importance of organizations like exchanges, that have very significant fiduciary duties, to undertake a systematic process after a security breach to eliminate all possible remaining vulnerabilities, no matter how unlikely and counterintuitive.
I think his point is that when it comes to stuff like this, our intuition about reasonable assumptions is wrong. And we must as both you and the parent post say, be systematic about the response.
It's a reasonable assumption, one move in advance. If you are thinking ahead of the immediate next move, then it is not. Clearly the person who outsmarted their security also exploited their naive human assumptions.
> I have to admit, that is a reasonable assumption.
It costs dirt to move your coins. It's not remotely reasonable if you're in the Bitcoin world at all - if you have any reason to believe that an attacker had any access to your wallet the advice is always the same. Make a new wallet and transfer all the coins ASAP.
They said it's a reasonable assumption to believe your private keys likely weren't compromised. That's not the same as saying it's reasonable to not move the coins anyway.
I have to admit, that is a reasonable assumption. This may show the limits of the usefulness of heuristics, and the importance of organizations like exchanges, that have very significant fiduciary duties, to undertake a systematic process after a security breach to eliminate all possible remaining vulnerabilities, no matter how unlikely and counterintuitive.