> I would not at all be surprised if the extortionist is very surprised that they did not have other backups and his actions have probably killed the company. > He's probably also somewhat worried, as this probably knocks the monetary damages up enough to (1) make it much more likely that this will get some serious law enforcement attention, and (2) if he is ever caught and convicted greatly increase his sentence and/or fine by moving the severity level of the offense way up.

That's plausible. It makes some sense that if you destroy something that you should be responsible for that. At the same time, even for a hacker the assumption that there would be back-ups would be a fairly logical one, though I'd hate to be in a position of fielding that defense.