So just how was he accepting it when it was the employer depositing it into his account? I don't get it. If they threatened legal action they're retards. They put the money into his account 3 months after termination? Good luck finding him at fault.
DT, it's your account, do with it what you wish. You've done your due diligence. Just hang onto any money you have (that you shouldn't have) to pay back when they pull their head out...
If you are receiving money into your account that you did not earn, you can be forced to pay it back. You cant tell me that you didn't know it wasnt in there. Bottom line, its not your money.