Sounds to me like Delta's trying to blame the guy for a problem they should have fixed. Passengers don't decide whether or not they get frequent flyer miles, Delta's computers do. If Delta sent the guy a letter in 2001, but didn't take the additional step of revoking "Cello Harrell's" frequent flyer status, it's their problem, not his. It's not his job to tell them his cello isn't a human, it's Delta's job to change their customer database to reflect that it's not a human. And now they're punishing him for their mistake.