I am not sure about the full story but I do hope that Bitfinex will be able to contact the team that is responsible for the hack. I really hope that the hackers will consider returning those Bitcoin to its original owners and explain how they manage to bypass Bitfinex's security. This can make Bitcoin stronger which is something that I believe every good Bitcoiners and tech-savvy people (like those hackers) wants.
On August 2nd the Hong Kong-based Bitcoin exchange Bitfinex was compromised for roughly $70 million worth of Bitcoin. According to sources, the attacker managed to drain the exchange through its multi-signature security gaining 120,000 BTC from the breach. Now the exchange is trying to reach out to the responsible party in an attempt to get its customers Bitcoin returned.https://news.bitcoin.com/bitfinex-seeks-bitcoin-thief/ The question is if bitfinex itself was the mastermind in the hacking. First and foremost bitfinex is a large company and has the capability of spending millions to investigate using very highly skilled programmers. It is just an opinion but I do hope bitfinex is guilt free and will be successful taking back the coins. Whether it inside job or done by outside hacker the bitcoin is impossible to retrieve.
I really doubt that it is an inside job though. I cannot understand why Bitfinex would want to do this if they already have enough profit from trading fees.