Online transfer dispute

We have a soon-to-be ex-husband claiming that his soon-to-be ex-wife logged in to his online banking (we do not allow dual enrollment - each person must have their own) and transferred money from his single party account to their joint savings account and then came into the bank and withdrew it. We do know that she came into the bank and withdrew money from the savings. Our online banking disclosure states of course that the bank may rely on anything done using your Access ID and passcode was done by you. We do believe that at one point they were probably sharing this User Id. Even though we only issue the ID to one person doesn't mean they don't share it. When the log-in was done for the transfer, the password was put in and accepted and the customer didn't have to answer any authentication questions which indicates it was done from a computer that had been used to log-on in the past. Luckily, this has not happened before so I need advice how to handle this please. Thank you.

IMO this becomes a legal issue between them and the bank should not get in the middle. How do you know he didn't make that transfer before they decided to separate and now he wants it back? Too many scenarios here, so he needs to change his pw and talk to his attorney.

Certainly it could be a valid Reg E claim but you have information indicating your customer did this, i.e. logon credentials, specific computer, etc. If the customer isn't claiming a hack, I would indicate the logon credentials were provided by him and not changed and the bank not notified. Because I think he is trying to get over on the bank, I'd say it indicates he did or allowed the transactions. Also, Reg E says an error is not one done by the consumer, with their authorization, or from which they benefitted. Clearly funds went to another of his accounts. He benefitted. No claim in my book.