Is it true the refund was in the form of an eCheck? One of you is doctoring the cut and pastes from PayPal, and it looks like you are.
If the money was sent and accepted to your Yahoo PayPal account, and you didn't remove it, it would have been refunded from your PayPal funds, immediately. Even if PayPal was holding the funds and had not released them to you yet they would have processed a refund immediately.
You have admitted to refunding the money from the second payment, meaning the payment was made and accepted by your Yahoo PayPal.
The only way your refund would have been in the form of an eCheck was if you emptied the Yahoo account (spent elsewhere, transferred, gifted to your other PayPal account, etc..) of the money he sent you before you initiated the refund.
Therefore you do still have the money.
If so you are not fooling anyone, and trying to wash your hands of it only makes you really look like a thief. You owe him his money back, or the knife he was trying to buy. What you posted above doesn't prove the refund was successful, just initiated.