1. If the robber is too good at hacking, Maybe he can get those bitcoin address in the history of the ATM but he can never get those private keys and get users account. The robbed money is never related to users fund so its from the operators account.
2. Everything is risky and its just an isolated case. Even fiat ATMs and banks are robbed. So its not that big deal to worry.
The hacker doesn't need to even try and inquire about the past transactions, not only it is futile but even if possible it's also a lot less lucrative than other alternatives.
That ATM was doing less than a thousand worth of transaction a day, the robber could have simply fed the ATM some cash, break the strong box (which was not strong at all) and reuse the cash for another tx or just walk away.
A bank ATM doesn't work like that, if I would try to load my debit card and then break the ATM to get my money it's pretty obvious who the culprit is.Also, bank ATMs are nothing like this card box that got trashed.
This is sad story. I bet they payed like $20 000 for this machine and some brainless yahoo's destroyed their's hopes and dreams of become Bitcoin ATM Tycoon's.
If they did pay 20k$ for that, then the real thieves were not the ones that destroyed the ATM but the ones that sold them that piece of junk.