As an aside, many people searched and none could find an orphaned block in their storage (bitcoin stores all blocks lost in reorgs) which contained a double spend against the main chain, making their claimed attack vector very unlikely. Moreover they refused to provide a copy of their blockchain file, which would have conclusively proved the attack. In light of this I believe it's far more likely that they gambled away or just outright stole the funds.

In any case, Bitcoin "takes advantage of the nature of information being easy to spread but hard to stifle"— you only need one honest connection to resist this kind of attack, and the attack can't be performed against reasonable client software that enforces a reasonable number of confirmations without a considerable cost in producing doomed blocks.