Did I not do the right thing for my friend or is he at fault or ?

A true friend would not ask you to lie under oath and risk having yourself charged with purgery, which could have you doing some jail time. My guess is that he knew the accident was probably his fault and wanted to use you to help get him off the hook. You were not wrong. You did the right thing. Leave him in the past with the memories. He doesn't sound like a trustworthy person.