Now if they had paid you $5 million, that might leave you open to a fraud charge if you spent it because you were never expecting that much. But if they paid you the $3 million they were going to pay you but just 10 years early…is it different?
That said, I reckon it’s clearly an error. ;)
Now you schedule a bill pay at your bank for back payments to your lender and your bank messes up and pays off the entire mortgage with their money.
The lender then recieves a lump sum payment from you which pays off the mortgage and they are happy.
Next three (or so) days he try to give it back and they wouldn't listen.
Next day after that they contact him to say he needs to give the money back immediately "or else".
The judge will NOT be friendly to the other side.