forget." and i said, "i know." and so we had to go through the driver's side 'cause the passenger side door was broke. >> couldn't open it. >> you could. oh, yeah. >> you could? >> you could. but to make it close correctly, you had to kinda lift it up and close it. >> was it common knowledge, roxy, that he had a car with a bum door? >> yep. >> reporter: and what roxy says happened next could be the key to the mystery. according to roxy, the bouncer stopped at her house first and dana got out to use the bathroom. then she helped dana get back into adkins' car, through what she remembers as a faulty passenger door. >> i walked her out there and put her in the car and i closed the door and i said, "i'll talk to you later." >> but you weren't gonna. >> and off they went. >> that is the goodbye. >> last time i'd seen her alive. >> do you beat yourself up, roxy, about that door and whether you closed -- >> i beat myself up -- >> -- it correctly? >> -- a lot. >> or? you know? >> uh-huh. i -- i thought about that for a long time. for a long time. >> what do you think happened? nobody knows. but what do you think happened there? you know the -- >> i -- >> -- vehicle. >> i think she fell out. i -- i think it was a freak accident. >> reporter: but if she was wrong, and dana was murdered,