It is showing you are using the Online version, with the Online version you can only prepare a return for one person or joint return per account. To prepare another return for someone else you need to create a new account (UserID & Password). If you did use the Online version than your return has overwritten your friends return & you cannot get it back.
If you used the Desktop version, your friends return is on your computer. Open the TurboTax software, choose File, then Open, select his return.