Something similar happened to me. A few years ago I had a paper ticket on DL and unfortunately stowed it in my back pocket where it likely flipped out in a parking lot when I got in or out of the car. I arrived at the airport and could not find the ticket. Delta allowed me to purchase a duplicate ticket and gave me a form to fill out to apply for compensation. This paper ticket faux pax happened to me twice that year. In each case Delta responded in writing that someone else had used my paper tickets and no compensation was due. So much for the photo i.d. check.