The thing is that this hack happens months ago and it's just this month that Coinbase acknowledge it.
So we don't know why it took them so long to take responsibility, in any case Coinbase are going to reimburse those 6000 customers that have been affected by the hacks.
Coinbase also says it will reimburse those who lost funds as a result of the phishing attack, and that it has already begun to make customers whole. The company did not disclose the total amount the hackers stole.
https://decrypt.co/82427/coinbase-hack-phishing